SELECT 
  category_id, 
  parent_id 
FROM 
  cscart_categories 
WHERE 
  parent_id IN(
    349, 335, 337, 350, 338, 339, 351, 352, 
    340, 341, 353, 354, 342, 343, 355, 356, 
    344, 345, 357, 358, 347, 336
  )

Query time 0.00076

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "28.02"
    },
    "table": {
      "table_name": "cscart_categories",
      "access_type": "ALL",
      "possible_keys": [
        "parent"
      ],
      "rows_examined_per_scan": 115,
      "rows_produced_per_join": 31,
      "filtered": "26.96",
      "cost_info": {
        "read_cost": "21.82",
        "eval_cost": "6.20",
        "prefix_cost": "28.02",
        "data_read_per_join": "83K"
      },
      "used_columns": [
        "category_id",
        "parent_id"
      ],
      "attached_condition": "(`eshopuga_upgr_4122`.`cscart_categories`.`parent_id` in (349,335,337,350,338,339,351,352,340,341,353,354,342,343,355,356,344,345,357,358,347,336))"
    }
  }
}