SELECT 
  category_id, 
  parent_id 
FROM 
  cscart_categories 
WHERE 
  parent_id IN(
    2304, 2303, 2302, 2305, 2306, 2309, 2307, 
    2308, 2314, 2312, 2310, 2311, 2313
  ) 
  AND category_id != 414

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "9.11"
    },
    "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": 13,
      "rows_produced_per_join": 13,
      "filtered": "100.00",
      "index_condition": "(`s2cart`.`cscart_categories`.`parent_id` in (2304,2303,2302,2305,2306,2309,2307,2308,2314,2312,2310,2311,2313))",
      "cost_info": {
        "read_cost": "7.81",
        "eval_cost": "1.30",
        "prefix_cost": "9.11",
        "data_read_per_join": "46K"
      },
      "used_columns": [
        "category_id",
        "parent_id"
      ],
      "attached_condition": "(`s2cart`.`cscart_categories`.`category_id` <> 414)"
    }
  }
}