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 (
    1787, 
    1660, 
    1705, 
    2334, 
    1912, 
    1706, 
    2325, 
    1938, 
    2290, 
    2344, 
    2345, 
    2347, 
    1748, 
    2122, 
    2348, 
    2349, 
    2145, 
    2027, 
    2350, 
    1989, 
    1712, 
    2021, 
    1803, 
    2129, 
    2007, 
    2327, 
    1975, 
    2144, 
    2000, 
    2016, 
    1900, 
    2075, 
    1899, 
    2025, 
    1905, 
    1937, 
    1988, 
    1946, 
    1789, 
    2338, 
    1904, 
    1945, 
    1941, 
    1942, 
    1998, 
    1972, 
    1974, 
    2341, 
    2020, 
    2023, 
    2018, 
    2017, 
    2339, 
    1995, 
    1742, 
    1694, 
    2013, 
    2012, 
    2342, 
    2022, 
    2026, 
    2019, 
    2024, 
    1973, 
    1659, 
    2343, 
    1983, 
    2336, 
    1902, 
    1992, 
    1980, 
    1994, 
    1926, 
    2137, 
    2138, 
    2351, 
    2088, 
    2082, 
    2080, 
    2083, 
    2092, 
    2084, 
    2093, 
    2086, 
    2085, 
    2087, 
    2089, 
    2081, 
    2090, 
    2167, 
    2168, 
    2094, 
    2095, 
    2096, 
    2097, 
    2107, 
    2291, 
    2278, 
    2297, 
    2280, 
    2293, 
    2281, 
    2294, 
    2170, 
    2282, 
    2299, 
    2283, 
    2284, 
    2285, 
    2286, 
    2287, 
    2288, 
    1930, 
    1721, 
    2123, 
    1959, 
    1984, 
    1935, 
    2337, 
    1768, 
    1978, 
    2362, 
    1723, 
    1727, 
    2364, 
    2169, 
    2106, 
    2105, 
    2268
  )

Query time 0.00191

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "135.46"
    },
    "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": 129,
          "rows_produced_per_join": 129,
          "filtered": "100.00",
          "index_condition": "(`gaseus`.`pfv`.`variant_id` in (1787,1660,1705,2334,1912,1706,2325,1938,2290,2344,2345,2347,1748,2122,2348,2349,2145,2027,2350,1989,1712,2021,1803,2129,2007,2327,1975,2144,2000,2016,1900,2075,1899,2025,1905,1937,1988,1946,1789,2338,1904,1945,1941,1942,1998,1972,1974,2341,2020,2023,2018,2017,2339,1995,1742,1694,2013,2012,2342,2022,2026,2019,2024,1973,1659,2343,1983,2336,1902,1992,1980,1994,1926,2137,2138,2351,2088,2082,2080,2083,2092,2084,2093,2086,2085,2087,2089,2081,2090,2167,2168,2094,2095,2096,2097,2107,2291,2278,2297,2280,2293,2281,2294,2170,2282,2299,2283,2284,2285,2286,2287,2288,1930,1721,2123,1959,1984,1935,2337,1768,1978,2362,1723,1727,2364,2169,2106,2105,2268))",
          "cost_info": {
            "read_cost": "77.41",
            "eval_cost": "12.90",
            "prefix_cost": "90.31",
            "data_read_per_join": "147K"
          },
          "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": 129,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "32.25",
            "eval_cost": "12.90",
            "prefix_cost": "135.46",
            "data_read_per_join": "402K"
          },
          "used_columns": [
            "variant_id",
            "variant",
            "lang_code"
          ]
        }
      }
    ]
  }
}