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 (
    1748, 
    1660, 
    1705, 
    2122, 
    1973, 
    1989, 
    2325, 
    1975, 
    1659, 
    2348, 
    2345, 
    2347, 
    2007, 
    1706, 
    1941, 
    1712, 
    2341, 
    2343, 
    1942, 
    1983, 
    2344, 
    1899, 
    1998, 
    2336, 
    1902, 
    1992, 
    2342, 
    1937, 
    1972, 
    1980, 
    2334, 
    1974, 
    1994, 
    1926, 
    1904, 
    1945, 
    1787, 
    1789, 
    1995, 
    1900, 
    1988, 
    1742, 
    1905, 
    1946, 
    2137, 
    2138, 
    2000, 
    2351, 
    2075, 
    1694, 
    2088, 
    2082, 
    2080, 
    2083, 
    2092, 
    2084, 
    2093, 
    2086, 
    2085, 
    2087, 
    2089, 
    1912, 
    2350, 
    2145, 
    2081, 
    2090, 
    2327, 
    1803, 
    2027, 
    2167, 
    2168, 
    2094, 
    2095, 
    2096, 
    2097, 
    2016, 
    2144, 
    2026, 
    2025, 
    2012, 
    2013, 
    2129, 
    2107, 
    2291, 
    2278, 
    2297, 
    2280, 
    2293, 
    2281, 
    2294, 
    2170, 
    2282, 
    2299, 
    2283, 
    2284, 
    2285, 
    2286, 
    2287, 
    2288, 
    1930, 
    1721, 
    2123, 
    1959, 
    1984, 
    2290, 
    1938, 
    2020, 
    2339, 
    2338, 
    2021, 
    2337, 
    1768, 
    1978, 
    2362, 
    1723, 
    1727, 
    2364, 
    2169, 
    2106, 
    2105, 
    2268, 
    2477, 
    2448, 
    2473, 
    2455, 
    2479, 
    2452, 
    2480, 
    2481, 
    2471, 
    2443, 
    1462, 
    2457, 
    1718, 
    2139, 
    2482, 
    2413, 
    2478, 
    2447, 
    2451, 
    2466, 
    2464, 
    2463, 
    2467, 
    2468, 
    2490, 
    2489, 
    2003, 
    1675, 
    2486, 
    2485, 
    2124, 
    1657, 
    1876
  )

Query time 0.00170

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "161.71"
    },
    "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": 154,
          "rows_produced_per_join": 154,
          "filtered": "100.00",
          "index_condition": "(`test2_gaseus`.`pfv`.`variant_id` in (1748,1660,1705,2122,1973,1989,2325,1975,1659,2348,2345,2347,2007,1706,1941,1712,2341,2343,1942,1983,2344,1899,1998,2336,1902,1992,2342,1937,1972,1980,2334,1974,1994,1926,1904,1945,1787,1789,1995,1900,1988,1742,1905,1946,2137,2138,2000,2351,2075,1694,2088,2082,2080,2083,2092,2084,2093,2086,2085,2087,2089,1912,2350,2145,2081,2090,2327,1803,2027,2167,2168,2094,2095,2096,2097,2016,2144,2026,2025,2012,2013,2129,2107,2291,2278,2297,2280,2293,2281,2294,2170,2282,2299,2283,2284,2285,2286,2287,2288,1930,1721,2123,1959,1984,2290,1938,2020,2339,2338,2021,2337,1768,1978,2362,1723,1727,2364,2169,2106,2105,2268,2477,2448,2473,2455,2479,2452,2480,2481,2471,2443,1462,2457,1718,2139,2482,2413,2478,2447,2451,2466,2464,2463,2467,2468,2490,2489,2003,1675,2486,2485,2124,1657,1876))",
          "cost_info": {
            "read_cost": "92.41",
            "eval_cost": "15.40",
            "prefix_cost": "107.81",
            "data_read_per_join": "175K"
          },
          "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": [
            "test2_gaseus.pfv.variant_id",
            "const"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 154,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "38.50",
            "eval_cost": "15.40",
            "prefix_cost": "161.71",
            "data_read_per_join": "480K"
          },
          "used_columns": [
            "variant_id",
            "variant",
            "lang_code"
          ]
        }
      }
    ]
  }
}