code: func (updater *OCSPUpdater) markExpired(status core.CertificateStatus) error {
  	_, err := updater.dbMap.Exec(
  		`UPDATE certificateStatus
   		SET isExpired = TRUE
   		WHERE serial = ?`,
  		status.Serial,
  	)
  	return err
  }
docs: // markExpired updates a given CertificateStatus to have `isExpired` set.