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 (
    5362, 5352, 5694, 5693, 5692, 5691, 5686, 
    5676, 5634, 5940, 26680, 6076, 6072, 
    6067, 6413, 6421, 6517, 6474, 6380, 
    6790
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00059

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE cscart_product_descriptions range PRIMARY,product_id PRIMARY 9 20 Using where

Result

product_id short_description full_description meta_keywords meta_description search_words promo_text
5352 DEFCA05,Defiance Recordings,Tom Berry
5362 DEFCA05,Defiance Recordings,Defiant DJS
5634 AWSUMCD01IT,AWsum,Zac H,Tom Berry
5676 AWSUMCD001,AWsum,Zac H,Tom Berry
5686 DEFCA02,Defiant Collection,Defiant DJS
5691 DEFCA02,Defiant Collection,Rob Cain,Klubfiller
5692 DEFCA02,Defiant Collection,Rezonance Q,Rob Cain
5693 DEFCA02,Defiant Collection,Tom Berry
5694 DEFCA02,Defiant Collection,XNRG
5940 NUSM007,NUsum,DJ Ransome
6067 DEFC02,Defiant Collection,Defiant DJS
6072 DEFC02,Defiant Collection,XNRG
6076 DEFC02,Defiant Collection,Rezonance Q,Rob Cain
6380 UDT02,Underdog Trax,Perifal
6413 UDT04,Underdog Trax,Mooney
6421 AWSMB004,AWsum,Wain Johnstone,Technikal
6474 DEF55,Defiance Recordings,XNRG
6517 UDT03,Underdog Trax,Streamline
6790 DEF52,Defiance Recordings,Rezonance Q,Rob Cain
26680 247HC051,24/7 Hardcore,Al Storm,Taya,Essex Boyz