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 (
    100653, 100652, 100651, 100650, 100649, 
    101334, 101333, 101332, 101331, 101330, 
    101329, 101328, 101327, 101326, 101325, 
    101324, 101323, 101322, 101321, 101320
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00066

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
100649 STMLP019,Stamina Records,A.B,Freedom
100650 STMLP019,Stamina Records,Stoker
100651 STMLP019,Stamina Records,Hedonistik Ritual
100652 STMLP019,Stamina Records,Transcend,TEDDY
100653 STMLP019,Stamina Records,SynthWulf
101320 UHCPT6,Megarave Records,The Freaky Bastard,Goetia
101321 UHCPT6,Megarave Records,Lunakorpz
101322 UHCPT6,Megarave Records,The Outcast
101323 UHCPT6,Megarave Records,Blooded Minds
101324 UHCPT6,Megarave Records,Mind Compressor
101325 UHCPT6,Megarave Records,Omistettu,KR1D
101326 UHCPT6,Megarave Records,Underground Vandalz
101327 UHCPT6,Megarave Records,Soulblast,Insane S
101328 UHCPT6,Megarave Records,Rizer
101329 UHCPT6,Megarave Records,VTK,Amon Gaara
101330 UHCPT6,Megarave Records,Miss Enemy
101331 UHCPT6,Megarave Records,Dj T-Go,Hardbouncer
101332 UHCPT6,Megarave Records,Insane S
101333 UHCPT6,Megarave Records,SRB
101334 UHCPT6,Megarave Records,Suicide Rage