SELECT 
  category_id, 
  parent_id 
FROM 
  cscart_categories 
WHERE 
  parent_id IN(
    216, 204, 210, 212, 211, 213, 209, 217, 
    215, 214, 208, 218
  ) 
  AND category_id != 264

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "11.11"
    },
    "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": 18,
      "rows_produced_per_join": 18,
      "filtered": "100.00",
      "index_condition": "(`demouniformecomd_db`.`cscart_categories`.`parent_id` in (216,204,210,212,211,213,209,217,215,214,208,218))",
      "cost_info": {
        "read_cost": "9.31",
        "eval_cost": "1.80",
        "prefix_cost": "11.11",
        "data_read_per_join": "46K"
      },
      "used_columns": [
        "category_id",
        "parent_id"
      ],
      "attached_condition": "(`demouniformecomd_db`.`cscart_categories`.`category_id` <> 264)"
    }
  }
}