SELECT 
  cscart_product_descriptions.product_id, 
  cscart_product_descriptions.unit_name 
FROM 
  cscart_product_descriptions 
WHERE 
  cscart_product_descriptions.product_id IN (
    17150, 17151, 17152, 17153, 17154, 17155, 
    17156, 17157, 17158, 17159, 17160, 
    17161, 17162, 17163, 17164, 17165
  ) 
  AND cscart_product_descriptions.lang_code = 'ru'

Query time 0.00093

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 (17150,17151,17152,17153,17154,17155,17156,17157,17158,17159,17160,17161,17162,17163,17164,17165) and cscart_product_descriptions.lang_code = 'ru'"
    }
  }
}