SELECT 
  product_id, 
  feature_short_desc 
FROM 
  cscart_ab__short_desc_from_features_values 
WHERE 
  product_id IN (
    21935, 21936, 21937, 21938, 21939, 21940, 
    21941, 21942, 21943, 21944, 21945, 
    21946, 21947, 21948, 21949, 21950
  ) 
  AND lang_code = 'ru' 
  AND storefront_id = 1

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_ab__short_desc_from_features_values",
      "access_type": "range",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "9",
      "used_key_parts": ["product_id", "lang_code"],
      "rows": 32,
      "filtered": 100,
      "attached_condition": "cscart_ab__short_desc_from_features_values.storefront_id = 1 and cscart_ab__short_desc_from_features_values.product_id in (21935,21936,21937,21938,21939,21940,21941,21942,21943,21944,21945,21946,21947,21948,21949,21950) and cscart_ab__short_desc_from_features_values.lang_code = 'ru'"
    }
  }
}