Each Applet you enable on IFTTT has information about how quickly it runs. You can see this information by selecting an Applet from your list of enabled Applets. You'll see some text near the bottom that states [Type] Applets usually run within [Time]. This is based on the time it usually takes similar Applets to run.
You also have the option to force a trigger check with the Check now button on this screen. Note that this will only cause your Applet to run if a new trigger event has occurred since the latest automatic check.
Users on the IFTTT Pro and Pro+ plans benefit from our fastest Applet speeds. If your Applets aren’t running as quickly as you'd expect, consider upgrading to IFTTT Pro or Pro+.
Most service owners have tools available to them to make their triggers realtime (more about it here). We encourage you to reach out to them if you think this would benefit your Applets.