SELECT 
  product_id, 
  feature_short_desc 
FROM 
  cscart_ab__short_desc_from_features_values 
WHERE 
  product_id IN (
    20765, 20766, 20767, 20768, 20769, 20770, 
    20771, 20772, 20773, 20774, 20775, 
    20776, 20777, 20778, 20779, 20780
  ) 
  AND lang_code = 'en' 
  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": 16,
      "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 (20765,20766,20767,20768,20769,20770,20771,20772,20773,20774,20775,20776,20777,20778,20779,20780) and cscart_ab__short_desc_from_features_values.lang_code = 'en'"
    }
  }
}