SELECT 
  category_id, 
  parent_id 
FROM 
  cscart_categories 
WHERE 
  parent_id IN(
    216, 204, 212, 210, 211, 213, 209, 217, 
    215, 214, 208, 218
  )

Query time 0.00022

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE cscart_categories ALL parent 83 Using where

Result

category_id parent_id
212 211
208 204
209 204
210 204
213 211
214 211
216 215
217 215
218 215