Sandbox

SELECT 
  cscart_ult_product_descriptions.product_id, 
  cscart_ult_product_descriptions.short_description, 
  IF(
    cscart_ult_product_descriptions.short_description = "", 
    cscart_ult_product_descriptions.full_description, 
    ""
  ) AS full_description, 
  cscart_ult_product_descriptions.meta_keywords, 
  cscart_ult_product_descriptions.meta_description, 
  cscart_ult_product_descriptions.search_words, 
  cscart_ult_product_descriptions.promo_text 
FROM 
  cscart_ult_product_descriptions 
WHERE 
  cscart_ult_product_descriptions.product_id IN (
    50522, 50521, 50520, 50519, 50518, 50517, 
    50516, 50515, 51281, 50485, 50484, 
    50462, 50461, 50103, 50447, 50408, 
    50465, 50464, 50463, 50393, 50389, 
    50388, 50387, 50072, 50267, 50234, 
    50233, 50232, 50231, 50230, 50229, 
    50228, 50227, 50226, 50225, 50224, 
    50223, 50067, 50066, 50065, 50064, 
    50275, 50274, 50269, 50265, 50039, 
    50001, 88490, 88489, 50040, 50034, 
    50033, 50025, 50152, 50151, 50124, 
    50123, 50122, 49944, 50110, 50107, 
    49954, 49953, 49952, 49951, 49950, 
    50219, 50218, 50217, 50216, 50215, 
    50214, 50213, 50212, 50211, 50210, 
    50209, 50208, 50207, 50206
  ) 
  AND cscart_ult_product_descriptions.company_id = 1 
  AND cscart_ult_product_descriptions.lang_code = 'en'

Query time 0.00045

Explain
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	cscart_ult_product_descriptions	ALL	PRIMARY,product_id,company_id				1	Using where