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 (
    48848, 49397, 49398, 49663, 49400, 49540, 
    49399, 49503, 49501, 49550, 49502, 
    49543, 49383, 49541, 49542, 49504, 
    49547, 49664, 49549, 49661, 49665, 
    49666, 49551, 49604, 49548, 50147, 
    49662, 50218, 49572, 50219, 50220
  )

Query time 0.00151

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": 31,
          "filtered": 100,
          "index_condition": "p.product_id in (48848,49397,49398,49663,49400,49540,49399,49503,49501,49550,49502,49543,49383,49541,49542,49504,49547,49664,49549,49661,49665,49666,49551,49604,49548,50147,49662,50218,49572,50219,50220)"
        }
      },
      {
        "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
        }
      }
    ]
  }
}