The 313.414 seconds is the time taken to read and restore the backup data. The rest of the time would be used to re-apply the uncommitted transactions from the redo log prior to the restore process, and also to undo any open transactions from the current restore process, and write them to the redo log.
If you want to confirm that this is indeed the case, try restoring a couple of trx logs with the NORECOVERY option. The total duration taken should be close to what SQL Server reports on the 'RESTORE LOG successfully processed...' line.
If you want to confirm that this is indeed the case, try restoring a couple of trx logs with the NORECOVERY option. The total duration taken should be close to what SQL Server reports on the 'RESTORE LOG successfully processed...' line.