SELECT 
  category_id, 
  parent_id 
FROM 
  cscart_categories 
WHERE 
  parent_id IN(
    1509, 1502, 1504, 1508, 1503, 1507, 1506, 
    1505, 1510, 1512, 1511, 1513, 1516, 
    1515, 1514, 1518, 1517
  ) 
  AND category_id != 414

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "11.91"
    },
    "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": 17,
      "rows_produced_per_join": 17,
      "filtered": "100.00",
      "index_condition": "(`s2cart`.`cscart_categories`.`parent_id` in (1509,1502,1504,1508,1503,1507,1506,1505,1510,1512,1511,1513,1516,1515,1514,1518,1517))",
      "cost_info": {
        "read_cost": "10.21",
        "eval_cost": "1.70",
        "prefix_cost": "11.91",
        "data_read_per_join": "60K"
      },
      "used_columns": [
        "category_id",
        "parent_id"
      ],
      "attached_condition": "(`s2cart`.`cscart_categories`.`category_id` <> 414)"
    }
  }
}