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SELECT 
  a.modifier, 
  a.modifier_type, 
  IF(
    shared_option_variants.variant_id IS NOT NULL, 
    shared_option_variants.modifier, 
    a.modifier
  ) as modifier, 
  IF(
    shared_option_variants.variant_id IS NOT NULL, 
    shared_option_variants.modifier_type, 
    a.modifier_type
  ) as modifier_type, 
  a.variant_id 
FROM 
  cscart_product_option_variants a 
  LEFT JOIN cscart_ult_product_option_variants shared_option_variants ON shared_option_variants.variant_id = a.variant_id 
  AND shared_option_variants.company_id = 1 
WHERE 
  1 
  AND a.variant_id IN (
    233054, 233053, 232387, 235845, 235876, 
    235939, 234770, 232485, 232511, 232268, 
    235954, 235980, 223749, 223755, 223760
  )

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "shared_option_variants",
      "access_type": "system",
      "possible_keys": ["PRIMARY", "company_id"],
      "rows": 0,
      "filtered": 0,
      "const_row_not_found": true
    },
    "table": {
      "table_name": "a",
      "access_type": "range",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "3",
      "used_key_parts": ["variant_id"],
      "rows": 15,
      "filtered": 100,
      "attached_condition": "a.variant_id in (233054,233053,232387,235845,235876,235939,234770,232485,232511,232268,235954,235980,223749,223755,223760)"
    }
  }
}

Result

modifier	modifier_type	variant_id
0.000	A	223749
0.000	A	223755
0.000	A	223760
0.000	A	232268
0.000	A	232387
0.000	A	232485
0.000	A	232511
0.000	A	233053
0.000	A	233054
0.000	A	234770
0.000	A	235845
0.000	A	235876
0.000	A	235939
0.000	A	235954
0.000	A	235980