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 (
    4896, 4381, 4361, 4822, 4347, 4343, 4713, 
    4714, 4684, 4718, 4717, 4685, 4715, 
    4716, 5093, 5092, 4804, 5341, 5340, 
    4346, 5206, 4421, 4382, 4780
  )

Query time 0.00068

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "f",
      "access_type": "ALL",
      "possible_keys": ["idx_group_id"],
      "rows": 6,
      "filtered": 100
    },
    "table": {
      "table_name": "g",
      "access_type": "eq_ref",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "3",
      "used_key_parts": ["id"],
      "ref": ["admin_test.f.group_id"],
      "rows": 1,
      "filtered": 100
    },
    "table": {
      "table_name": "p",
      "access_type": "ALL",
      "possible_keys": ["PRIMARY", "idx_group_id"],
      "rows": 15,
      "filtered": 80,
      "attached_condition": "p.group_id = f.group_id and p.product_id in (4896,4381,4361,4822,4347,4343,4713,4714,4684,4718,4717,4685,4715,4716,5093,5092,4804,5341,5340,4346,5206,4421,4382,4780)"
    }
  }
}