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 (
    2187, 2260, 1861, 1747, 1780, 1797, 1823, 
    1782, 1798, 1772, 1755, 2028, 2118, 
    2116, 2117, 1966, 1967, 1965, 2026, 
    2027, 2131, 1938, 2025, 2062, 2369, 
    1856, 2205, 1846, 1885, 1873, 1824, 
    1869, 2004, 2140, 2139, 2141, 2150, 
    1935, 2003, 2007, 2076, 1867, 2029, 
    2361, 1825, 1826, 2390, 2391, 2270, 
    2272, 2273, 2308, 2378, 2220, 2022, 
    2015, 1980, 1976, 1927, 2058, 1975, 
    1964, 2136, 1749, 1973, 2339, 1974, 
    2354, 1972, 2352, 2030, 2269, 2289, 
    2167, 2128, 1968, 1969, 2192, 2297, 
    2037
  )

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "2.33"
    },
    "nested_loop": [
      {
        "table": {
          "table_name": "f",
          "access_type": "ALL",
          "possible_keys": [
            "idx_group_id"
          ],
          "rows_examined_per_scan": 2,
          "rows_produced_per_join": 2,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "0.52",
            "eval_cost": "0.20",
            "prefix_cost": "0.72",
            "data_read_per_join": "208"
          },
          "used_columns": [
            "feature_id",
            "purpose",
            "group_id"
          ]
        }
      },
      {
        "table": {
          "table_name": "g",
          "access_type": "eq_ref",
          "possible_keys": [
            "PRIMARY"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "id"
          ],
          "key_length": "3",
          "ref": [
            "cscartdevel.f.group_id"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 2,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "0.50",
            "eval_cost": "0.20",
            "prefix_cost": "1.42",
            "data_read_per_join": "800"
          },
          "used_columns": [
            "id",
            "code"
          ]
        }
      },
      {
        "table": {
          "table_name": "p",
          "access_type": "ALL",
          "possible_keys": [
            "PRIMARY",
            "idx_group_id"
          ],
          "rows_examined_per_scan": 2,
          "rows_produced_per_join": 4,
          "filtered": "100.00",
          "using_join_buffer": "hash join",
          "cost_info": {
            "read_cost": "0.51",
            "eval_cost": "0.40",
            "prefix_cost": "2.33",
            "data_read_per_join": "64"
          },
          "used_columns": [
            "product_id",
            "parent_product_id",
            "group_id"
          ],
          "attached_condition": "((`cscartdevel`.`p`.`group_id` = `cscartdevel`.`f`.`group_id`) and (`cscartdevel`.`p`.`product_id` in (2187,2260,1861,1747,1780,1797,1823,1782,1798,1772,1755,2028,2118,2116,2117,1966,1967,1965,2026,2027,2131,1938,2025,2062,2369,1856,2205,1846,1885,1873,1824,1869,2004,2140,2139,2141,2150,1935,2003,2007,2076,1867,2029,2361,1825,1826,2390,2391,2270,2272,2273,2308,2378,2220,2022,2015,1980,1976,1927,2058,1975,1964,2136,1749,1973,2339,1974,2354,1972,2352,2030,2269,2289,2167,2128,1968,1969,2192,2297,2037)))"
        }
      }
    ]
  }
}