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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 (
    68280, 68279, 68278, 68277, 68276, 68275, 
    68274, 68575, 68204, 68406, 68375, 
    78288, 78287, 78286, 78285, 78284, 
    78283, 78282, 78281, 78280, 78279, 
    78278, 78277, 78276, 78275, 78274, 
    78273, 78272, 78271, 78270, 78269, 
    78268, 78267, 78266, 78265, 78264, 
    78263, 78262, 68395, 68189
  )

Query time 0.00025

Explain
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	p	ALL	PRIMARY,idx_group_id				376	Using where
1	SIMPLE	g	eq_ref	PRIMARY	PRIMARY	3	toolboxdigitalshop_dev.p.group_id	1
1	SIMPLE	f	ref	idx_group_id	idx_group_id	3	toolboxdigitalshop_dev.p.group_id	7