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 (
    1926, 1973, 2347, 2345, 2341, 2348, 1659, 
    2082, 2325, 1705, 1660, 1748, 2080, 
    2083, 2092, 2084, 2093, 2086, 2085, 
    2088, 2087, 2089, 1912, 1712, 2344, 
    2290, 1938, 2327, 1803, 2016, 1900, 
    1902, 1995, 2000, 2090, 1941, 2097, 
    2096, 2095, 2094, 1988, 2025, 1899, 
    1905, 1787, 2020, 2350, 2339, 1983, 
    2291, 2278, 2297, 2280, 2293, 2281, 
    2294, 2170, 2282, 2026, 1904, 1789, 
    1946, 1937, 2299, 2283, 2284, 2285, 
    2286, 2287, 2288, 1942, 1998, 1945, 
    2075, 1930, 1959, 1984, 1975, 1974, 
    1972, 1721, 2337, 1768, 2081
  )

Query time 0.00096

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "88.21"
    },
    "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": 84,
          "rows_produced_per_join": 84,
          "filtered": "100.00",
          "index_condition": "(`gaseus`.`pfv`.`variant_id` in (1926,1973,2347,2345,2341,2348,1659,2082,2325,1705,1660,1748,2080,2083,2092,2084,2093,2086,2085,2088,2087,2089,1912,1712,2344,2290,1938,2327,1803,2016,1900,1902,1995,2000,2090,1941,2097,2096,2095,2094,1988,2025,1899,1905,1787,2020,2350,2339,1983,2291,2278,2297,2280,2293,2281,2294,2170,2282,2026,1904,1789,1946,1937,2299,2283,2284,2285,2286,2287,2288,1942,1998,1945,2075,1930,1959,1984,1975,1974,1972,1721,2337,1768,2081))",
          "cost_info": {
            "read_cost": "50.41",
            "eval_cost": "8.40",
            "prefix_cost": "58.81",
            "data_read_per_join": "95K"
          },
          "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": [
            "gaseus.pfv.variant_id",
            "const"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 84,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "21.00",
            "eval_cost": "8.40",
            "prefix_cost": "88.21",
            "data_read_per_join": "261K"
          },
          "used_columns": [
            "variant_id",
            "variant",
            "lang_code"
          ]
        }
      }
    ]
  }
}