SELECT 
  product_id 
FROM 
  cscart_product_bundle_product_links 
WHERE 
  bundle_id = 1631 
  AND show_on_product_page = 'N'

Query time 0.00027

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE cscart_product_bundle_product_links ref bundle_id bundle_id 4 const 15 Using where

Result

product_id
103792
103793
103794
103795
103796
103797
103798
103799
103800
103801
103802
103803
103804
103805