SELECT 
  category_id, 
  parent_id 
FROM 
  cscart_categories 
WHERE 
  parent_id IN(
    915, 443, 886, 421, 435, 881, 440, 425, 
    888, 450, 428, 889, 887, 460, 467, 471
  )

Query time 0.00068

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE cscart_categories range parent parent 3 25 Using index condition

Result

category_id parent_id
915 421
435 421
881 421
888 421
450 421
460 421
467 421
471 421
886 425
440 425
889 425
443 428
887 428