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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 (
    13878, 13877, 13876, 13875, 13874, 13873, 
    13872, 13870, 13869, 13829, 13862, 
    13858, 13850, 13849, 13848, 13847, 
    13846, 13845, 13844, 13843, 13842, 
    13841, 13840, 13839, 13838, 13837, 
    13836, 13835, 13834, 13833, 13832, 
    13831, 13830, 13827, 13826, 13825, 
    13824, 13823, 13822, 13821
  )

Query time 0.00019

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