SELECT 
  category_id, 
  parent_id 
FROM 
  cscart_categories 
WHERE 
  parent_id IN(
    3017, 2916, 2920, 266, 5299, 4922, 6456, 
    3816, 4486, 447, 2910, 443, 3648, 1505, 
    1518, 10425, 10426, 3308, 3550, 3573, 
    3616, 3642, 3685, 3751, 3913
  )

Query time 0.00111

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "98.39"
    },
    "table": {
      "table_name": "cscart_categories",
      "access_type": "range",
      "possible_keys": [
        "parent"
      ],
      "key": "parent",
      "used_key_parts": [
        "parent_id"
      ],
      "key_length": "3",
      "rows_examined_per_scan": 243,
      "rows_produced_per_join": 243,
      "filtered": "100.00",
      "using_index": true,
      "cost_info": {
        "read_cost": "49.79",
        "eval_cost": "48.60",
        "prefix_cost": "98.39",
        "data_read_per_join": "1M"
      },
      "used_columns": [
        "category_id",
        "parent_id"
      ],
      "attached_condition": "(`webmarco`.`cscart_categories`.`parent_id` in (3017,2916,2920,266,5299,4922,6456,3816,4486,447,2910,443,3648,1505,1518,10425,10426,3308,3550,3573,3616,3642,3685,3751,3913))"
    }
  }
}