SELECT 
  id_path 
FROM 
  cscart_categories 
WHERE 
  category_id IN (359, 365, 369, 986, 993, 987, 988)

Query time 0.00039

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE cscart_categories range PRIMARY,p_category_id,idx_category_id PRIMARY 3 7 Using index condition

Result

id_path
261/901/359
261/901/365
261/901/369
261/901/986
261/901/987
261/901/988
261/901/993