SELECT 
  category_id 
FROM 
  cscart_categories 
WHERE 
  id_path LIKE '737/%'

Query time 0.00056

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE cscart_categories range id_path,idx_id_path id_path 767 20 Using index condition

Result

category_id
746
747
902
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
808
813
814
998
999
904
924
927
930
961
962
963
964
965
966
967
968
969
970
971
972
973