SELECT 
  SQL_CALC_FOUND_ROWS (
    CASE WHEN products.parent_product_id <> 0 THEN products.parent_product_id ELSE products.product_id END
  ) AS product_id, 
  descr1.product as product, 
  companies.company as company_name, 
  COALESCE(
    cscart_master_products_storefront_min_price.price, 
    MIN(
      IF(
        prices.percentage_discount = 0, 
        prices.price, 
        prices.price - (
          prices.price * prices.percentage_discount
        )/ 100
      )
    )
  ) as price, 
  GROUP_CONCAT(
    products.product_id 
    ORDER BY 
      products.parent_product_id ASC, 
      products.product_id ASC
  ) AS product_ids, 
  GROUP_CONCAT(
    products.product_type 
    ORDER BY 
      products.parent_product_id ASC, 
      products.product_id ASC
  ) AS product_types, 
  GROUP_CONCAT(
    products.parent_product_id 
    ORDER BY 
      products.parent_product_id ASC, 
      products.product_id ASC
  ) AS parent_product_ids, 
  products.product_type, 
  products.parent_product_id, 
  products.master_product_offers_count, 
  products.master_product_id, 
  products.company_id, 
  IF(
    products.age_verification = 'Y', 
    'Y', 
    IF(
      cscart_categories.age_verification = 'Y', 
      'Y', cscart_categories.parent_age_verification
    )
  ) as need_age_verification, 
  IF(
    products.age_limit > cscart_categories.age_limit, 
    IF(
      products.age_limit > cscart_categories.parent_age_limit, 
      products.age_limit, cscart_categories.parent_age_limit
    ), 
    IF(
      cscart_categories.age_limit > cscart_categories.parent_age_limit, 
      cscart_categories.age_limit, cscart_categories.parent_age_limit
    )
  ) as age_limit, 
  1 as instock_marker, 
  IF(
    products.product_type = 'C', 
    (
      SELECT 
        MAX(amount) 
      FROM 
        cscart_products 
      WHERE 
        parent_product_id = products.product_id
    ) > 0, 
    IF(
      IF(
        products.tracking = 'O', 
        (
          SELECT 
            MAX(amount) 
          FROM 
            cscart_product_options_inventory s_inventory 
          WHERE 
            s_inventory.product_id = products.product_id
        ) > 0, 
        products.amount > 0
      ), 
      1, 
      IF(products.tracking = 'D', 1, 0)
    )
  ) as instock_sorting 
FROM 
  cscart_products as products 
  LEFT JOIN cscart_product_descriptions as descr1 ON descr1.product_id = products.product_id 
  AND descr1.lang_code = 'en' 
  LEFT JOIN cscart_product_prices as prices ON prices.product_id = products.product_id 
  AND prices.lower_limit = 1 
  LEFT JOIN cscart_companies AS companies ON companies.company_id = products.company_id 
  INNER JOIN cscart_products_categories as products_categories ON products_categories.product_id = products.product_id 
  INNER JOIN cscart_categories ON cscart_categories.category_id = products_categories.category_id 
  AND (
    cscart_categories.usergroup_ids = '' 
    OR FIND_IN_SET(
      0, cscart_categories.usergroup_ids
    ) 
    OR FIND_IN_SET(
      1, cscart_categories.usergroup_ids
    )
  ) 
  AND cscart_categories.status IN ('A', 'H') 
  AND cscart_categories.storefront_id IN (0, 1) 
  LEFT JOIN cscart_warehouses_sum_products_amount as war_sum_amount ON war_sum_amount.product_id = products.product_id 
  LEFT JOIN cscart_master_products_storefront_offers_count AS master_products_storefront_offers_count ON master_products_storefront_offers_count.product_id = products.product_id 
  AND master_products_storefront_offers_count.storefront_id = 1 
  LEFT JOIN cscart_master_products_storefront_min_price ON cscart_master_products_storefront_min_price.product_id = prices.product_id 
  AND cscart_master_products_storefront_min_price.storefront_id = 1 
WHERE 
  1 
  AND cscart_categories.category_id IN (
    1974, 
    1143, 
    1144, 
    1145, 
    1146, 
    1147, 
    1148, 
    1149, 
    1150, 
    1151, 
    1152, 
    1153, 
    1154, 
    1155, 
    1156, 
    1157, 
    1158, 
    1159, 
    1160, 
    1161, 
    1162, 
    1163, 
    1164, 
    1165, 
    1166, 
    1167, 
    1168, 
    1169, 
    1170, 
    1171, 
    1172, 
    1173, 
    1174, 
    1175, 
    1176, 
    1177, 
    1178, 
    1179, 
    1180, 
    1181, 
    1182, 
    1183, 
    1184, 
    1185, 
    1186, 
    1187, 
    1188, 
    1189, 
    1190, 
    1191, 
    1921, 
    1975, 
    1976, 
    1977, 
    1978, 
    1979, 
    1980, 
    1984, 
    1985, 
    1986, 
    1987, 
    1988, 
    1989, 
    1990, 
    1991, 
    1992, 
    1993, 
    2007, 
    2020, 
    2021, 
    2022, 
    2023, 
    2024, 
    2025, 
    2026, 
    2027, 
    2045, 
    2046, 
    2049, 
    2050, 
    2051, 
    2052, 
    2053, 
    2054, 
    2055, 
    2056, 
    2057, 
    2058, 
    2059, 
    2060, 
    2061, 
    2065, 
    2066, 
    2067, 
    2068, 
    2069, 
    2125, 
    2126, 
    2127, 
    2128, 
    2140, 
    2141, 
    2142, 
    2167, 
    2179, 
    2180, 
    2181, 
    2182, 
    2183, 
    2184, 
    2185, 
    2186, 
    2187, 
    2188, 
    2189, 
    2190, 
    2191, 
    2192, 
    2193, 
    2205, 
    2206, 
    2207, 
    2208, 
    2209, 
    2210, 
    2211, 
    2212, 
    2213, 
    2214, 
    2215, 
    2216, 
    2217, 
    2219, 
    2220, 
    2221, 
    2222, 
    2223, 
    2224, 
    2225, 
    2226, 
    2227, 
    2228, 
    2229, 
    2230, 
    2231, 
    2232, 
    2233, 
    2234, 
    2235, 
    2236, 
    2237, 
    2238, 
    2239, 
    2240, 
    2241, 
    2242, 
    2243, 
    2244, 
    2245, 
    2291, 
    2292, 
    2293, 
    2295, 
    2296, 
    2297, 
    2298, 
    2299, 
    2316, 
    2317, 
    2318, 
    2319
  ) 
  AND (
    companies.status IN ('A', 'S') 
    OR products.company_id = 0
  ) 
  AND products.company_id IN (137, 138, 146, 0) 
  AND (
    products.usergroup_ids = '' 
    OR FIND_IN_SET(0, products.usergroup_ids) 
    OR FIND_IN_SET(1, products.usergroup_ids)
  ) 
  AND products.status IN ('A') 
  AND prices.usergroup_id IN (0, 0, 1) 
  AND products.master_product_status IN ('A') 
  AND products.master_product_id = 0 
  AND (
    products.company_id > 0 
    OR (
      master_products_storefront_offers_count.count > 0
    )
  ) 
  AND products.product_type != 'D' 
GROUP BY 
  product_id 
ORDER BY 
  instock_sorting DESC, 
  price asc, 
  products.product_id ASC 
LIMIT 
  0, 20

Query time 0.05380

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "3098.47"
    },
    "ordering_operation": {
      "using_filesort": true,
      "grouping_operation": {
        "using_temporary_table": true,
        "using_filesort": true,
        "buffer_result": {
          "using_temporary_table": true,
          "nested_loop": [
            {
              "table": {
                "table_name": "war_sum_amount",
                "access_type": "system",
                "possible_keys": [
                  "PRIMARY"
                ],
                "rows_examined_per_scan": 0,
                "rows_produced_per_join": 1,
                "filtered": "0.00",
                "const_row_not_found": true,
                "cost_info": {
                  "read_cost": "0.00",
                  "eval_cost": "0.10",
                  "prefix_cost": "0.00",
                  "data_read_per_join": "16"
                },
                "used_columns": [
                  "product_id"
                ]
              }
            },
            {
              "table": {
                "table_name": "master_products_storefront_offers_count",
                "access_type": "system",
                "possible_keys": [
                  "PRIMARY",
                  "idx_storefront_id"
                ],
                "rows_examined_per_scan": 0,
                "rows_produced_per_join": 1,
                "filtered": "0.00",
                "const_row_not_found": true,
                "cost_info": {
                  "read_cost": "0.00",
                  "eval_cost": "0.10",
                  "prefix_cost": "0.00",
                  "data_read_per_join": "16"
                },
                "used_columns": [
                  "storefront_id",
                  "product_id",
                  "count"
                ]
              }
            },
            {
              "table": {
                "table_name": "cscart_master_products_storefront_min_price",
                "access_type": "system",
                "possible_keys": [
                  "PRIMARY"
                ],
                "rows_examined_per_scan": 0,
                "rows_produced_per_join": 1,
                "filtered": "0.00",
                "const_row_not_found": true,
                "cost_info": {
                  "read_cost": "0.00",
                  "eval_cost": "0.10",
                  "prefix_cost": "0.00",
                  "data_read_per_join": "16"
                },
                "used_columns": [
                  "storefront_id",
                  "product_id",
                  "price"
                ]
              }
            },
            {
              "table": {
                "table_name": "products_categories",
                "access_type": "range",
                "possible_keys": [
                  "PRIMARY",
                  "pt"
                ],
                "key": "PRIMARY",
                "used_key_parts": [
                  "category_id"
                ],
                "key_length": "3",
                "rows_examined_per_scan": 9762,
                "rows_produced_per_join": 9762,
                "filtered": "100.00",
                "using_index": true,
                "cost_info": {
                  "read_cost": "1037.47",
                  "eval_cost": "976.20",
                  "prefix_cost": "2013.67",
                  "data_read_per_join": "152K"
                },
                "used_columns": [
                  "product_id",
                  "category_id"
                ],
                "attached_condition": "(`s2cart`.`products_categories`.`category_id` in (1974,1143,1144,1145,1146,1147,1148,1149,1150,1151,1152,1153,1154,1155,1156,1157,1158,1159,1160,1161,1162,1163,1164,1165,1166,1167,1168,1169,1170,1171,1172,1173,1174,1175,1176,1177,1178,1179,1180,1181,1182,1183,1184,1185,1186,1187,1188,1189,1190,1191,1921,1975,1976,1977,1978,1979,1980,1984,1985,1986,1987,1988,1989,1990,1991,1992,1993,2007,2020,2021,2022,2023,2024,2025,2026,2027,2045,2046,2049,2050,2051,2052,2053,2054,2055,2056,2057,2058,2059,2060,2061,2065,2066,2067,2068,2069,2125,2126,2127,2128,2140,2141,2142,2167,2179,2180,2181,2182,2183,2184,2185,2186,2187,2188,2189,2190,2191,2192,2193,2205,2206,2207,2208,2209,2210,2211,2212,2213,2214,2215,2216,2217,2219,2220,2221,2222,2223,2224,2225,2226,2227,2228,2229,2230,2231,2232,2233,2234,2235,2236,2237,2238,2239,2240,2241,2242,2243,2244,2245,2291,2292,2293,2295,2296,2297,2298,2299,2316,2317,2318,2319))"
              }
            },
            {
              "table": {
                "table_name": "products",
                "access_type": "eq_ref",
                "possible_keys": [
                  "PRIMARY",
                  "status",
                  "idx_master_product_id"
                ],
                "key": "PRIMARY",
                "used_key_parts": [
                  "product_id"
                ],
                "key_length": "3",
                "ref": [
                  "s2cart.products_categories.product_id"
                ],
                "rows_examined_per_scan": 1,
                "rows_produced_per_join": 488,
                "filtered": "5.00",
                "cost_info": {
                  "read_cost": "0.00",
                  "eval_cost": "48.81",
                  "prefix_cost": "2989.87",
                  "data_read_per_join": "3M"
                },
                "used_columns": [
                  "product_id",
                  "product_type",
                  "status",
                  "company_id",
                  "amount",
                  "usergroup_ids",
                  "tracking",
                  "age_verification",
                  "age_limit",
                  "parent_product_id",
                  "master_product_id",
                  "master_product_status",
                  "master_product_offers_count"
                ],
                "attached_condition": "((`s2cart`.`products`.`master_product_id` = 0) and (`s2cart`.`products`.`company_id` in (137,138,146,0)) and ((`s2cart`.`products`.`usergroup_ids` = '') or (0 <> find_in_set(0,`s2cart`.`products`.`usergroup_ids`)) or (0 <> find_in_set(1,`s2cart`.`products`.`usergroup_ids`))) and (`s2cart`.`products`.`status` = 'A') and (`s2cart`.`products`.`master_product_status` = 'A') and ((`s2cart`.`products`.`company_id` > 0) or <cache>((NULL > 0))) and (`s2cart`.`products`.`product_type` <> 'D'))"
              }
            },
            {
              "table": {
                "table_name": "companies",
                "access_type": "eq_ref",
                "possible_keys": [
                  "PRIMARY"
                ],
                "key": "PRIMARY",
                "used_key_parts": [
                  "company_id"
                ],
                "key_length": "4",
                "ref": [
                  "s2cart.products.company_id"
                ],
                "rows_examined_per_scan": 1,
                "rows_produced_per_join": 488,
                "filtered": "100.00",
                "cost_info": {
                  "read_cost": "0.00",
                  "eval_cost": "48.81",
                  "prefix_cost": "3038.68",
                  "data_read_per_join": "4M"
                },
                "used_columns": [
                  "company_id",
                  "status",
                  "company"
                ],
                "attached_condition": "<if>(found_match(companies), ((`s2cart`.`companies`.`status` in ('A','S')) or (`s2cart`.`products`.`company_id` = 0)), true)"
              }
            },
            {
              "table": {
                "table_name": "cscart_categories",
                "access_type": "eq_ref",
                "possible_keys": [
                  "PRIMARY",
                  "c_status",
                  "p_category_id"
                ],
                "key": "PRIMARY",
                "used_key_parts": [
                  "category_id"
                ],
                "key_length": "3",
                "ref": [
                  "s2cart.products_categories.category_id"
                ],
                "rows_examined_per_scan": 1,
                "rows_produced_per_join": 24,
                "filtered": "5.00",
                "cost_info": {
                  "read_cost": "0.00",
                  "eval_cost": "2.44",
                  "prefix_cost": "3087.49",
                  "data_read_per_join": "86K"
                },
                "used_columns": [
                  "category_id",
                  "usergroup_ids",
                  "status",
                  "age_verification",
                  "age_limit",
                  "parent_age_verification",
                  "parent_age_limit",
                  "storefront_id"
                ],
                "attached_condition": "(((`s2cart`.`cscart_categories`.`usergroup_ids` = '') or (0 <> find_in_set(0,`s2cart`.`cscart_categories`.`usergroup_ids`)) or (0 <> find_in_set(1,`s2cart`.`cscart_categories`.`usergroup_ids`))) and (`s2cart`.`cscart_categories`.`status` in ('A','H')) and (`s2cart`.`cscart_categories`.`storefront_id` in (0,1)))"
              }
            },
            {
              "table": {
                "table_name": "descr1",
                "access_type": "eq_ref",
                "possible_keys": [
                  "PRIMARY",
                  "product_id"
                ],
                "key": "PRIMARY",
                "used_key_parts": [
                  "product_id",
                  "lang_code"
                ],
                "key_length": "9",
                "ref": [
                  "s2cart.products_categories.product_id",
                  "const"
                ],
                "rows_examined_per_scan": 1,
                "rows_produced_per_join": 24,
                "filtered": "100.00",
                "cost_info": {
                  "read_cost": "0.00",
                  "eval_cost": "2.44",
                  "prefix_cost": "3089.93",
                  "data_read_per_join": "184K"
                },
                "used_columns": [
                  "product_id",
                  "lang_code",
                  "product"
                ]
              }
            },
            {
              "table": {
                "table_name": "prices",
                "access_type": "ref",
                "possible_keys": [
                  "usergroup",
                  "product_id",
                  "lower_limit",
                  "usergroup_id"
                ],
                "key": "product_id",
                "used_key_parts": [
                  "product_id"
                ],
                "key_length": "3",
                "ref": [
                  "s2cart.products_categories.product_id"
                ],
                "rows_examined_per_scan": 1,
                "rows_produced_per_join": 24,
                "filtered": "100.00",
                "cost_info": {
                  "read_cost": "6.10",
                  "eval_cost": "2.44",
                  "prefix_cost": "3098.47",
                  "data_read_per_join": "585"
                },
                "used_columns": [
                  "product_id",
                  "price",
                  "percentage_discount",
                  "lower_limit",
                  "usergroup_id"
                ],
                "attached_condition": "((`s2cart`.`prices`.`lower_limit` = 1) and (`s2cart`.`prices`.`usergroup_id` in (0,0,1)))"
              }
            }
          ],
          "select_list_subqueries": [
            {
              "dependent": true,
              "cacheable": false,
              "query_block": {
                "select_id": 3,
                "message": "no matching row in const table"
              }
            },
            {
              "dependent": true,
              "cacheable": false,
              "query_block": {
                "select_id": 2,
                "cost_info": {
                  "query_cost": "31651.29"
                },
                "table": {
                  "table_name": "cscart_products",
                  "access_type": "ALL",
                  "possible_keys": [
                    "idx_parent_product_id"
                  ],
                  "rows_examined_per_scan": 270845,
                  "rows_produced_per_join": 27084,
                  "filtered": "10.00",
                  "cost_info": {
                    "read_cost": "4566.79",
                    "eval_cost": "2708.45",
                    "prefix_cost": "31651.29",
                    "data_read_per_join": "203M"
                  },
                  "used_columns": [
                    "amount",
                    "parent_product_id"
                  ],
                  "attached_condition": "(`s2cart`.`cscart_products`.`parent_product_id` = `s2cart`.`products`.`product_id`)"
                }
              }
            }
          ]
        }
      }
    }
  }
}