SELECT 
  cscart_product_descriptions.product_id, 
  cscart_product_descriptions.short_description, 
  IF(
    cscart_product_descriptions.short_description = '' 
    OR cscart_product_descriptions.short_description IS NULL, 
    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 (295, 285) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_product_descriptions",
      "access_type": "range",
      "possible_keys": ["PRIMARY", "product_id"],
      "key": "PRIMARY",
      "key_length": "9",
      "used_key_parts": ["product_id", "lang_code"],
      "rows": 2,
      "filtered": 100,
      "index_condition": "((cscart_product_descriptions.product_id in (295,285)) and (cscart_product_descriptions.lang_code = 'en'))"
    }
  }
}

Result

product_id short_description full_description meta_keywords meta_description search_words promo_text
285 <p><b>Holden</b>: Captiva SUV</p> <p><b>Model</b>&nbsp;:</p> <p><b>Year</b>: December 07</p> <p><b>Colour</b>: Silver&nbsp;</p> <p><b>Paint</b>&nbsp;Code:</p> <p><b>Motor</b>:</p> <p><b>Millage</b>: 185694 km</p> <p><b>Vehicle Damage</b></p> <p>Slight front Right</p> HOLDEN CAPTIVA SILVER SUV 07 WRECKING HOLDEN CAPTIVA SILVER SUV 07 WRECKING captiva, silver, 2007, holden
295 <p>Wrecking&nbsp;1992 Holden Rodeo 4cyl Petrol Auto 357,626kms</p> Rodeo, White rodeo, wrecking white holden rodeo, ​Wrecking 1992 Holden, Rodeo,4cyl,Petrol,Auto