SELECT 
  cscart_product_descriptions.product_id, 
  cscart_product_descriptions.short_description, 
  IF(
    cscart_product_descriptions.short_description = '', 
    cscart_product_descriptions.full_description, 
    ''
  ) AS full_description, 
  cscart_product_descriptions.meta_keywords, 
  cscart_product_descriptions.meta_description, 
  cscart_product_descriptions.search_words, 
  cscart_product_descriptions.promo_text 
FROM 
  cscart_product_descriptions 
WHERE 
  cscart_product_descriptions.product_id IN (5098, 5066, 5067, 5069, 5068) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_product_descriptions",
      "access_type": "range",
      "possible_keys": ["PRIMARY", "product_id"],
      "key": "product_id",
      "key_length": "3",
      "used_key_parts": ["product_id"],
      "rows": 5,
      "filtered": 100,
      "index_condition": "cscart_product_descriptions.product_id in (5098,5066,5067,5069,5068)",
      "attached_condition": "cscart_product_descriptions.lang_code = 'en'"
    }
  }
}

Result

product_id short_description full_description meta_keywords meta_description search_words promo_text
5066 <p>Universal carry holder for APX XE models </p>
5067 <p>Leather Carry Case with 3” Fixed Belt Loop </p>
5068 <p>Leather Carry Case with 3” Fixed Belt Loop </p>
5069 <p>Leather Carry Case with D-Rings and 2.75” Swivel Belt Loop </p>
5098