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 (
    41340, 5990, 27359, 5789, 47922, 47921, 
    41343, 47896, 47924, 47923, 3517, 5991, 
    3516, 35782, 3518, 40445, 40442, 22172, 
    47024, 1278, 41293, 40446, 1716, 47020, 
    47023, 47022, 48980, 40443, 27353, 
    37850, 2873, 3577
  )

Query time 0.00161

JSON explain

{
  "query_block": {
    "select_id": 1,
    "nested_loop": [
      {
        "table": {
          "table_name": "p",
          "access_type": "range",
          "possible_keys": ["PRIMARY", "idx_group_id"],
          "key": "PRIMARY",
          "key_length": "3",
          "used_key_parts": ["product_id"],
          "rows": 32,
          "filtered": 100,
          "index_condition": "p.product_id in (41340,5990,27359,5789,47922,47921,41343,47896,47924,47923,3517,5991,3516,35782,3518,40445,40442,22172,47024,1278,41293,40446,1716,47020,47023,47022,48980,40443,27353,37850,2873,3577)"
        }
      },
      {
        "table": {
          "table_name": "f",
          "access_type": "ref",
          "possible_keys": ["idx_group_id"],
          "key": "idx_group_id",
          "key_length": "3",
          "used_key_parts": ["group_id"],
          "ref": ["dev_db.p.group_id"],
          "rows": 1,
          "filtered": 100
        }
      },
      {
        "table": {
          "table_name": "g",
          "access_type": "eq_ref",
          "possible_keys": ["PRIMARY"],
          "key": "PRIMARY",
          "key_length": "3",
          "used_key_parts": ["id"],
          "ref": ["dev_db.p.group_id"],
          "rows": 1,
          "filtered": 100
        }
      }
    ]
  }
}