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 = 'ar' 
WHERE 
  pfv.variant_id IN (
    1587, 1751, 1562, 1750, 1526, 1748, 1749, 
    1684, 1560, 1687, 1766, 1682, 1591, 
    1561, 1773, 1775, 1563, 1776, 1774, 
    1778, 1755, 1558, 1779, 1780, 1781, 
    1782, 1554, 1785, 1564, 1786, 1760, 
    1787, 1788, 1789, 1761, 1762, 1737, 
    1738, 1739, 1740, 1559, 5991, 1600, 
    2315, 5563
  )

Query time 0.00212

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "47.26"
    },
    "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": 45,
          "rows_produced_per_join": 45,
          "filtered": "100.00",
          "index_condition": "(`softwarepirmam_hewadelivard_cscart_4`.`pfv`.`variant_id` in (1587,1751,1562,1750,1526,1748,1749,1684,1560,1687,1766,1682,1591,1561,1773,1775,1563,1776,1774,1778,1755,1558,1779,1780,1781,1782,1554,1785,1564,1786,1760,1787,1788,1789,1761,1762,1737,1738,1739,1740,1559,5991,1600,2315,5563))",
          "cost_info": {
            "read_cost": "27.01",
            "eval_cost": "4.50",
            "prefix_cost": "31.51",
            "data_read_per_join": "51K"
          },
          "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": 45,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "11.25",
            "eval_cost": "4.50",
            "prefix_cost": "47.26",
            "data_read_per_join": "136K"
          },
          "used_columns": [
            "variant_id",
            "variant",
            "lang_code"
          ]
        }
      }
    ]
  }
}