SELECT 
  category_id, 
  parent_id 
FROM 
  cscart_categories 
WHERE 
  parent_id IN(
    235, 167, 168, 198, 176, 178, 190, 255, 
    182, 175, 197, 236, 185, 169, 191, 193, 
    199, 240, 179, 186, 174, 234, 194, 200, 
    180, 238, 202, 187, 181, 195, 177, 237, 
    196, 188, 254, 189, 165, 170, 171, 172, 
    201, 263
  )

Query time 0.00053

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
165 167
168 167
169 167
170 167
171 167
172 167
176 175
178 177
179 177
180 177
181 177
182 177
199 196
185 175
186 175
187 175
188 175
189 175
190 174
191 174
194 174
193 174
195 174
197 196
198 196
200 196
201 167
202 175
235 234
236 234
237 234
238 234
240 234
255 263
263 254