SELECT 
  pfv.variant_id, 
  pfv.position, 
  pfvd.variant 
FROM 
  cscart_product_feature_variants AS pfv 
  INNER JOIN cscart_product_feature_variant_descriptions AS pfvd ON pfv.variant_id = pfvd.variant_id 
  AND pfvd.lang_code = 'en' 
WHERE 
  pfv.variant_id IN (
    1563, 1560, 1562, 1561, 1559, 1614, 1633, 
    1687, 1553, 1637, 1636, 1635, 1634, 
    1613, 1526, 1773, 1775, 1776, 1774, 
    2910, 1653, 2907, 2908, 1684, 2870, 
    1596, 1600, 2758, 2985, 1558, 2315, 
    4839, 5064, 5063, 6971, 1681, 2077, 
    6250, 1754, 1607, 1912
  )

Query time 0.00132

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "43.06"
    },
    "nested_loop": [
      {
        "table": {
          "table_name": "pfv",
          "access_type": "range",
          "possible_keys": [
            "PRIMARY"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "variant_id"
          ],
          "key_length": "3",
          "rows_examined_per_scan": 41,
          "rows_produced_per_join": 41,
          "filtered": "100.00",
          "index_condition": "(`softwarepirmam_hewadelivard_cscart_4`.`pfv`.`variant_id` in (1563,1560,1562,1561,1559,1614,1633,1687,1553,1637,1636,1635,1634,1613,1526,1773,1775,1776,1774,2910,1653,2907,2908,1684,2870,1596,1600,2758,2985,1558,2315,4839,5064,5063,6971,1681,2077,6250,1754,1607,1912))",
          "cost_info": {
            "read_cost": "24.61",
            "eval_cost": "4.10",
            "prefix_cost": "28.71",
            "data_read_per_join": "46K"
          },
          "used_columns": [
            "variant_id",
            "position"
          ]
        }
      },
      {
        "table": {
          "table_name": "pfvd",
          "access_type": "eq_ref",
          "possible_keys": [
            "PRIMARY"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "variant_id",
            "lang_code"
          ],
          "key_length": "9",
          "ref": [
            "softwarepirmam_hewadelivard_cscart_4.pfv.variant_id",
            "const"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 41,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "10.25",
            "eval_cost": "4.10",
            "prefix_cost": "43.06",
            "data_read_per_join": "123K"
          },
          "used_columns": [
            "variant_id",
            "variant",
            "lang_code"
          ]
        }
      }
    ]
  }
}