SELECT 
  category_id, 
  category 
FROM 
  cscart_category_descriptions 
WHERE 
  category_id IN (
    337, 338, 339, 340, 341, 342, 343, 344, 
    345, 349, 350, 351, 352, 353, 354, 355, 
    356, 357, 358, 370, 371, 372, 373, 374, 
    375, 376, 377, 378, 379, 381, 382, 383, 
    384, 385, 386
  ) 
  AND lang_code = 'nl'

Query time 0.00064

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "84.01"
    },
    "table": {
      "table_name": "cscart_category_descriptions",
      "access_type": "range",
      "possible_keys": [
        "PRIMARY"
      ],
      "key": "PRIMARY",
      "used_key_parts": [
        "category_id",
        "lang_code"
      ],
      "key_length": "9",
      "rows_examined_per_scan": 35,
      "rows_produced_per_join": 35,
      "filtered": "100.00",
      "index_condition": "((`eshopuga_upgr_4122`.`cscart_category_descriptions`.`category_id` in (337,338,339,340,341,342,343,344,345,349,350,351,352,353,354,355,356,357,358,370,371,372,373,374,375,376,377,378,379,381,382,383,384,385,386)) and (`eshopuga_upgr_4122`.`cscart_category_descriptions`.`lang_code` = 'nl'))",
      "cost_info": {
        "read_cost": "77.01",
        "eval_cost": "7.00",
        "prefix_cost": "84.01",
        "data_read_per_join": "116K"
      },
      "used_columns": [
        "category_id",
        "lang_code",
        "category"
      ]
    }
  }
}