SELECT 
  f.feature_id, 
  f.purpose, 
  p.product_id, 
  p.parent_product_id, 
  g.id, 
  g.code 
FROM 
  cscart_product_variation_group_features AS f 
  INNER JOIN cscart_product_variation_groups AS g ON f.group_id = g.id 
  INNER JOIN cscart_product_variation_group_products AS p ON f.group_id = p.group_id 
WHERE 
  p.product_id IN (
    40303, 40302, 40301, 40300, 40299, 40298, 
    40297, 79897, 39728, 39507, 39506, 
    39377, 39398, 39447, 39332, 39319, 
    39318, 39313, 39267, 39266, 39265, 
    39264, 39263, 39260, 39259, 39641, 
    39255, 39247, 39246, 39225, 39224, 
    39223, 39184, 39183, 39270, 39147, 
    39393, 39391, 39390, 39389, 39387, 
    39385, 39383, 39382, 39381, 39644, 
    39144, 39143, 39142, 39141, 39140, 
    39139, 39138, 39137, 39136, 39135, 
    39134, 39133, 39132, 39131, 39130, 
    39129, 39128, 39127, 39069, 39068, 
    39067, 39066, 39065, 39064, 79921, 
    39118, 39117, 39116, 39115, 39034, 
    70800, 70799, 70798, 70797
  )

Query time 0.00066

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE f ALL idx_group_id 46
1 SIMPLE g eq_ref PRIMARY PRIMARY 3 toolboxdigitalshop_dev.f.group_id 1
1 SIMPLE p ref PRIMARY,idx_group_id idx_group_id 3 toolboxdigitalshop_dev.f.group_id 16 Using where