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 (
    1912, 
    1904, 
    2026, 
    2083, 
    1803, 
    2362, 
    1723, 
    1659, 
    1660, 
    2348, 
    2080, 
    1945, 
    1705, 
    1905, 
    1946, 
    2087, 
    2364, 
    1727, 
    2085, 
    1988, 
    2288, 
    2090, 
    2341, 
    1926, 
    1712, 
    2345, 
    2347, 
    2285, 
    2088, 
    2283, 
    2086, 
    2170, 
    2084, 
    2280, 
    2095, 
    1973, 
    2093, 
    2092, 
    2089, 
    2082, 
    1941, 
    2016, 
    2096, 
    1899, 
    2025, 
    2106, 
    2105, 
    2097, 
    1900, 
    2327, 
    1787, 
    1789, 
    2169, 
    1995, 
    1937, 
    1942, 
    1998, 
    2325, 
    2145, 
    1989, 
    2350, 
    2144, 
    2168, 
    2027, 
    2122, 
    2007, 
    2337, 
    1721, 
    1706, 
    2094, 
    2167, 
    1742, 
    2343, 
    1972, 
    1974, 
    1980, 
    2075, 
    1768, 
    2081, 
    1983, 
    2338, 
    2020, 
    2339, 
    1975, 
    2021, 
    1978, 
    2299, 
    2294, 
    2297, 
    2287, 
    2286, 
    2284, 
    2293, 
    2291, 
    2282, 
    2281, 
    2278, 
    2000, 
    2012, 
    2107, 
    1694, 
    2129, 
    2013, 
    1984, 
    1959, 
    2290, 
    1938, 
    2344, 
    2334, 
    2024, 
    2023, 
    2342, 
    2349, 
    2017, 
    1935, 
    1930, 
    2336, 
    2123, 
    2351, 
    1902, 
    1992, 
    2137, 
    2268, 
    2022, 
    2019, 
    2018, 
    1994, 
    1748, 
    2138, 
    2381, 
    2378, 
    1954, 
    1836, 
    2132, 
    2130, 
    2143, 
    2131, 
    1949, 
    2403, 
    2133, 
    2134, 
    2135, 
    2136, 
    2388, 
    2408, 
    2409, 
    2410, 
    2411, 
    2413, 
    2415, 
    2423, 
    2424, 
    2426, 
    2173, 
    2497, 
    2541, 
    2043, 
    2370, 
    2374, 
    2499, 
    2501, 
    2369, 
    2373, 
    2147, 
    1879, 
    1829, 
    2124, 
    2524
  )

Query time 0.00240

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "155.46"
    },
    "nested_loop": [
      {
        "table": {
          "table_name": "pfv",
          "access_type": "ALL",
          "possible_keys": [
            "PRIMARY"
          ],
          "rows_examined_per_scan": 950,
          "rows_produced_per_join": 168,
          "filtered": "17.68",
          "cost_info": {
            "read_cost": "79.86",
            "eval_cost": "16.80",
            "prefix_cost": "96.66",
            "data_read_per_join": "191K"
          },
          "used_columns": [
            "variant_id",
            "position"
          ],
          "attached_condition": "(`test2_gaseus`.`pfv`.`variant_id` in (1912,1904,2026,2083,1803,2362,1723,1659,1660,2348,2080,1945,1705,1905,1946,2087,2364,1727,2085,1988,2288,2090,2341,1926,1712,2345,2347,2285,2088,2283,2086,2170,2084,2280,2095,1973,2093,2092,2089,2082,1941,2016,2096,1899,2025,2106,2105,2097,1900,2327,1787,1789,2169,1995,1937,1942,1998,2325,2145,1989,2350,2144,2168,2027,2122,2007,2337,1721,1706,2094,2167,1742,2343,1972,1974,1980,2075,1768,2081,1983,2338,2020,2339,1975,2021,1978,2299,2294,2297,2287,2286,2284,2293,2291,2282,2281,2278,2000,2012,2107,1694,2129,2013,1984,1959,2290,1938,2344,2334,2024,2023,2342,2349,2017,1935,1930,2336,2123,2351,1902,1992,2137,2268,2022,2019,2018,1994,1748,2138,2381,2378,1954,1836,2132,2130,2143,2131,1949,2403,2133,2134,2135,2136,2388,2408,2409,2410,2411,2413,2415,2423,2424,2426,2173,2497,2541,2043,2370,2374,2499,2501,2369,2373,2147,1879,1829,2124,2524))"
        }
      },
      {
        "table": {
          "table_name": "pfvd",
          "access_type": "eq_ref",
          "possible_keys": [
            "PRIMARY"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "variant_id",
            "lang_code"
          ],
          "key_length": "9",
          "ref": [
            "test2_gaseus.pfv.variant_id",
            "const"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 168,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "42.00",
            "eval_cost": "16.80",
            "prefix_cost": "155.46",
            "data_read_per_join": "523K"
          },
          "used_columns": [
            "variant_id",
            "variant",
            "lang_code"
          ]
        }
      }
    ]
  }
}