Reduce the number of lookback days in the scan. 100 (trading) days of data (5 months) should be sufficient for most scans (depending of course on your trading style.)

Reduce the number of stocks scanned. You can scan all the stocks in TeleChart if you like, but it would be best to narrow your search to certain sectors, or to your own watch lists.

Narrow down your filter criteria - reduce the price and volume range of the stocks you are interested in trading.

If you have it on, turn off the Show Charts while scan is running option. With this option set the scan time will be greatly increased.

In Pattern Scans, use the Built-In Pattern Mode instead of the Editable Pattern Mode.  Also, to display charts faster, turn off the Show Past Patterns option.