SELECT 
  category_id, 
  category 
FROM 
  cscart_category_descriptions 
WHERE 
  category_id IN (738, 750) 
  AND lang_code = 'fr'

Query time 0.00032

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE cscart_category_descriptions range PRIMARY PRIMARY 9 2 Using index condition

Result

category_id category
738 Maçonnerie
750 Mortiers & adhésifs