SELECT 
  cscart_product_descriptions.product_id, 
  cscart_product_descriptions.unit_name 
FROM 
  cscart_product_descriptions 
WHERE 
  cscart_product_descriptions.product_id IN (
    23023, 23024, 23025, 23026, 23027, 23028, 
    23029, 23030, 23031, 23032, 23033, 
    23034, 23035, 23036, 23037, 23038
  ) 
  AND cscart_product_descriptions.lang_code = 'ru'

Query time 0.00331

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_product_descriptions",
      "access_type": "range",
      "possible_keys": ["PRIMARY", "product_id", "idx_product_lang"],
      "key": "PRIMARY",
      "key_length": "9",
      "used_key_parts": ["product_id", "lang_code"],
      "rows": 16,
      "filtered": 100,
      "index_condition": "cscart_product_descriptions.product_id in (23023,23024,23025,23026,23027,23028,23029,23030,23031,23032,23033,23034,23035,23036,23037,23038) and cscart_product_descriptions.lang_code = 'ru'"
    }
  }
}