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 (
    1904, 1905, 1906, 1907, 1908, 1909, 1910, 
    1911, 1912, 1913, 1914, 1915, 1916, 
    1917, 1918, 1919, 1920, 1921, 1922, 
    1923, 1924, 1925, 1926, 1927, 1928, 
    1929, 1930, 1931, 5560, 5561, 5562, 
    5563, 5564, 5565, 5566, 5567, 5568, 
    5569, 5570, 5571, 5572, 5573, 5574, 
    5575, 5576, 5577, 5578, 5579
  )

Query time 0.00068

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "168.01"
    },
    "nested_loop": [
      {
        "table": {
          "table_name": "p",
          "access_type": "range",
          "possible_keys": [
            "PRIMARY",
            "idx_group_id"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "product_id"
          ],
          "key_length": "3",
          "rows_examined_per_scan": 48,
          "rows_produced_per_join": 48,
          "filtered": "100.00",
          "index_condition": "(`test2_gaseus`.`p`.`product_id` in (1904,1905,1906,1907,1908,1909,1910,1911,1912,1913,1914,1915,1916,1917,1918,1919,1920,1921,1922,1923,1924,1925,1926,1927,1928,1929,1930,1931,5560,5561,5562,5563,5564,5565,5566,5567,5568,5569,5570,5571,5572,5573,5574,5575,5576,5577,5578,5579))",
          "cost_info": {
            "read_cost": "28.81",
            "eval_cost": "4.80",
            "prefix_cost": "33.61",
            "data_read_per_join": "768"
          },
          "used_columns": [
            "product_id",
            "parent_product_id",
            "group_id"
          ]
        }
      },
      {
        "table": {
          "table_name": "g",
          "access_type": "eq_ref",
          "possible_keys": [
            "PRIMARY"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "id"
          ],
          "key_length": "3",
          "ref": [
            "test2_gaseus.p.group_id"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 48,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "12.00",
            "eval_cost": "4.80",
            "prefix_cost": "50.41",
            "data_read_per_join": "18K"
          },
          "used_columns": [
            "id",
            "code"
          ]
        }
      },
      {
        "table": {
          "table_name": "f",
          "access_type": "ref",
          "possible_keys": [
            "idx_group_id"
          ],
          "key": "idx_group_id",
          "used_key_parts": [
            "group_id"
          ],
          "key_length": "3",
          "ref": [
            "test2_gaseus.p.group_id"
          ],
          "rows_examined_per_scan": 7,
          "rows_produced_per_join": 336,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "84.00",
            "eval_cost": "33.60",
            "prefix_cost": "168.01",
            "data_read_per_join": "34K"
          },
          "used_columns": [
            "feature_id",
            "purpose",
            "group_id"
          ]
        }
      }
    ]
  }
}