SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43b520ad534cb59f30d29262b335e217adb8bc6651a390419311f89b7d1dacfe' 
  AND token = 'EY/vW+XigtB4a6D8Gl+/vAoEG95JZE6z+60l+vqwzvI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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