SELECT 
  id_path 
FROM 
  cscart_categories 
WHERE 
  category_id IN (
    338, 340, 349, 350, 351, 352, 353, 354, 
    355, 356, 357, 358, 359, 360, 361, 362, 
    363, 368, 388, 390, 391, 392, 393, 394, 
    395, 396
  )

Query time 0.00081

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "28.02"
    },
    "table": {
      "table_name": "cscart_categories",
      "access_type": "ALL",
      "possible_keys": [
        "PRIMARY",
        "p_category_id"
      ],
      "rows_examined_per_scan": 115,
      "rows_produced_per_join": 26,
      "filtered": "22.61",
      "cost_info": {
        "read_cost": "22.82",
        "eval_cost": "5.20",
        "prefix_cost": "28.02",
        "data_read_per_join": "69K"
      },
      "used_columns": [
        "category_id",
        "id_path"
      ],
      "attached_condition": "(`eshopuga_upgr_4122`.`cscart_categories`.`category_id` in (338,340,349,350,351,352,353,354,355,356,357,358,359,360,361,362,363,368,388,390,391,392,393,394,395,396))"
    }
  }
}