SELECT 
  category_id, 
  category, 
  description, 
  lang_code 
FROM 
  cscart_category_descriptions 
WHERE 
  category_id = 251

Query time 0.00029

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE cscart_category_descriptions ref PRIMARY PRIMARY 3 const 7

Result

category_id category description lang_code
251 Calculators de
251 Calculators en
251 Calculators es
251 Calculators fr
251 Calculators ru
251 Calculators uk