Your brain isn't somehow over locking itself, you just remember everything about the event in detail, so it feels like it in retrospect
The subconscious knowledge of this is why we've internalized and re-expressed the "judgement upon death" notion across many religions.
Under normal circumstances when looking at a random car, you most likely just see a car. You've probably seen a car before so it's not something you need to pay attention to.
But under the influence of psychedelics you pay attention to all the details of the car. Like how it's somehow symmetrical in shape, the reflection of the car from the sun, transparent windows that somehow reflects the environment a little bit but is still somehow lets you see the inside of the car, the front part of the car looks like a face, the car is larger than you, etc, etc.
The experience under the influence might feel like it took 2 minutes, but in reality it probably took 10 seconds. It can feel even longer when recalling the memory.
(you might also see things that aren't part of the car but I'm leaving that out here to talk about how long an experience feels like)
As a child, nearly every day is packed with novel stimuli. The number of distinct “imprints” on your memory during this time is extremely high. In other words, you have a higher “memory density” during this period compared to when you’re older and the mind uses these reference points as a proxy for the passage of time.
It follows that you can lead a “longer” life by prioritizing novel experiences over routines.
In terms of untrained optimization, though, autopilot is prioritized. I think this is pretty well corroborated by Kahneman's chimera in Thinking, Fast and Slow but I think it's less of a metabolic thing than it is an interruption in train of thought.
Perhaps this is derived by the fact the mind can create its own feedback loops, and in the circumstances where you've mastered to the point of intuition and reflexivity some practice, those feedback loops are given precedence because they're more rewarding, and being called to the real world becomes frustrating. At least that's how I'd assemble my own experience in narrative.
If you've ever been anesthetized for a medical operation, it really feels like the moment you lose awareness to the moment you wake up again is the same event, except that 15 hours has passed in between.
I've heard people who fall unconscious from head trauma say the same thing. Suddenly they wake up in hospital not knowing what has happened.
It reminds me of that statement in Starship Troopers (the book): "The death rate's the same for us as for anyone. One person, one death, sooner or later."