SELECT 
  category_id, 
  parent_id 
FROM 
  cscart_categories 
WHERE 
  parent_id IN(
    267, 271, 285, 286, 290, 294, 302, 311, 
    315, 326, 334, 342, 346, 350, 355, 361
  )

Query time 0.00174

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "17.89"
    },
    "table": {
      "table_name": "cscart_categories",
      "access_type": "ALL",
      "possible_keys": [
        "parent"
      ],
      "rows_examined_per_scan": 157,
      "rows_produced_per_join": 132,
      "filtered": "84.71",
      "cost_info": {
        "read_cost": "4.59",
        "eval_cost": "13.30",
        "prefix_cost": "17.89",
        "data_read_per_join": "853K"
      },
      "used_columns": [
        "category_id",
        "parent_id"
      ],
      "attached_condition": "(`zdrowy_db`.`cscart_categories`.`parent_id` in (267,271,285,286,290,294,302,311,315,326,334,342,346,350,355,361))"
    }
  }
}