SELECT 
  category_id, 
  parent_id 
FROM 
  cscart_categories 
WHERE 
  parent_id IN(
    2373, 2376, 2381, 2385, 2415, 2419, 2420, 
    2421, 2422, 2443, 2448, 2449, 2450, 
    2460, 2464, 2466, 2483, 2496, 2498, 
    2588, 2627, 2628, 2629, 2630, 2634, 
    2638, 2643, 2675, 2679, 2687
  ) 
  AND category_id != 414

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "26.86"
    },
    "table": {
      "table_name": "cscart_categories",
      "access_type": "range",
      "possible_keys": [
        "PRIMARY",
        "parent",
        "p_category_id"
      ],
      "key": "parent",
      "used_key_parts": [
        "parent_id"
      ],
      "key_length": "3",
      "rows_examined_per_scan": 43,
      "rows_produced_per_join": 43,
      "filtered": "100.00",
      "index_condition": "(`s2cart`.`cscart_categories`.`parent_id` in (2373,2376,2381,2385,2415,2419,2420,2421,2422,2443,2448,2449,2450,2460,2464,2466,2483,2496,2498,2588,2627,2628,2629,2630,2634,2638,2643,2675,2679,2687))",
      "cost_info": {
        "read_cost": "22.56",
        "eval_cost": "4.30",
        "prefix_cost": "26.86",
        "data_read_per_join": "152K"
      },
      "used_columns": [
        "category_id",
        "parent_id"
      ],
      "attached_condition": "(`s2cart`.`cscart_categories`.`category_id` <> 414)"
    }
  }
}