SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1505a98030366ed2162f69f54991ea27d1cd10b66de0f38abe19af3a302549ae' 
  AND token = 'YoACmxstNQTwj4bRLErwlXbgLfDO0z1HbQAksU6HvFU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}