The thing about making a decision is that you have to know what your choices are.
Or: the thing about acting under fire is that fire is bloody obvious.
This discussion is unfortunately going to have to start with
0) K:DL is a flawed implementation of some of the ideas from Apocalypse World.
Apocalypse World made act under fire, the obvious ancestor of K:DL's act under pressure move, linked to a single stat in large part because its smaller number of statistics and character types let it sensibly define who was cool and who wasn't through a limited number of starting stat arrays. The Battlebabe was cool. The Angel was kind of cool. The Hardholder could only be cool at great cost.
K:DL throws that out and lets anybody be as cool as they want to be, right from the start. But the free definition of stats by players carries with it the expectation of good and bad choices, characters out of balance with one another, instead of covering each others' weaknesses. So that's a bad place to start from.
1) Cool guys can't do anything special.
What's act under pressure let you do? Get away, get out, get through. Things anyone could do. The pressure's what makes them tough.
Can "anyone" do great things, difficult things? If "anyone" could then they would. While it's true that "anyone" in the right place at the right time can make a big impact, does "anyone" know the right place, or the right time?
There are certain plot structures you can plug "anyone" into. A secretive GM mastermind gives the PCs a shiny golden MacGuffin and tells them to run it through a tortuous obstacle course, after which it'll do something important on the other side. But in a story like that, the PCs are just doing what they're told. PbtA games don't work too well with PCs who just have to do what they're told.
The structure of most moves let PCs prioritize their own problems or take the risks to implement their own solutions - and there are some Coolness Advantages that work like this. All that act under pressure really does is set you up to get into a situation where you can make an impact, usually through another move or sometimes by virtue of narration.
But all that said, when you're coming from the narrative and trying to work out a fitting move to represent the problems PCs are facing, they're going to be under pressure a whole heck of a lot. So how do you make the call?
2) The pressure's what makes them tough.
An easy way to determine whether act under pressure is the most appropriate move to make is whether or not the pressure is the most important thing - if the PC could pull this off, no problem, if they were only among friends and had enough time to breathe. Every move assumes there's some sort of pressure in play; the GM often gets chances to express it on a 10-14 and always on a 9-. Broadly speaking, there are three types of situations where act under pressure isn't appropriate:
The PC doesn't know what to do. This applies to things that are plainly impossible, like leaping out a twenty-story window and finding a way to defy gravity before you hit pavement. It also includes things that require special training or preparation to accomplish, like some of the things covered by Advantages - disarming bombs, swaying entire crowds, maintaining a network of contacts.
The PC can't know exactly what to do. Some things are too chaotic for there to be a course of action you know in advance, where the tough part is the execution under pressure. Things like winning a fight (engage in combat), getting someone to do what you want (influence other), or seeing the truth behind the misty shapes of reality (see through the illusion).
The PC needs to find out what to do. This is one of your example scenarios: you get lost and need to find the way. This matches something you can find out with observe a situation: "What's my best way through this?" PCs may also need to understand NPC motivations (read a person) or analyze elements of a mystery (investigate) in order to take action.
In cases where the PCs need to find out what to do, it can often make sense to require them to act under pressure to do it once they find out. Like disarming a trap - if the trap doesn't have an obvious way to disarm it, observing a situation and asking "What should I be on the lookout for?" or "What is being hidden from me?" can provide that information. But if the trap is itself a source of pressure, even when they know how it's done PCs can still need to act under pressure to actually pull it off.