SELECT 
  cscart_product_feature_variants.variant_id, 
  cscart_product_feature_variants.position, 
  cscart_product_feature_variants.color, 
  cscart_product_feature_variant_descriptions.variant 
FROM 
  cscart_product_feature_variants 
  LEFT JOIN cscart_product_feature_variant_descriptions ON cscart_product_feature_variants.variant_id = cscart_product_feature_variant_descriptions.variant_id 
  AND cscart_product_feature_variant_descriptions.lang_code = 'en' 
WHERE 
  cscart_product_feature_variants.variant_id IN (
    125, 1855, 1856, 422, 473, 474, 600, 601, 
    602, 604, 58, 1930, 611, 612, 613, 1870, 
    50, 617, 633, 47, 636, 48, 654, 540, 1892, 
    890, 75, 1354, 49, 59, 1699, 1765, 590, 
    837, 905, 0, 91, 2986, 64, 2982, 2526, 
    2987
  ) 
ORDER BY 
  cscart_product_feature_variants.position ASC, 
  cscart_product_feature_variant_descriptions.variant ASC

Query time 0.00087

JSON explain

{
  "query_block": {
    "select_id": 1,
    "filesort": {
      "sort_key": "cscart_product_feature_variants.position, cscart_product_feature_variant_descriptions.variant",
      "temporary_table": {
        "nested_loop": [
          {
            "table": {
              "table_name": "cscart_product_feature_variants",
              "access_type": "range",
              "possible_keys": ["PRIMARY"],
              "key": "PRIMARY",
              "key_length": "3",
              "used_key_parts": ["variant_id"],
              "rows": 42,
              "filtered": 100,
              "index_condition": "cscart_product_feature_variants.variant_id in (125,1855,1856,422,473,474,600,601,602,604,58,1930,611,612,613,1870,50,617,633,47,636,48,654,540,1892,890,75,1354,49,59,1699,1765,590,837,905,0,91,2986,64,2982,2526,2987)"
            }
          },
          {
            "table": {
              "table_name": "cscart_product_feature_variant_descriptions",
              "access_type": "eq_ref",
              "possible_keys": ["PRIMARY"],
              "key": "PRIMARY",
              "key_length": "9",
              "used_key_parts": ["variant_id", "lang_code"],
              "ref": [
                "lillyshop_lillyshop.cscart_product_feature_variants.variant_id",
                "const"
              ],
              "rows": 1,
              "filtered": 100,
              "attached_condition": "trigcond(cscart_product_feature_variant_descriptions.lang_code = 'en')"
            }
          }
        ]
      }
    }
  }
}