Varied Timing- an even tempo no matter how fast can be understood around the 3-4 count; you pick up the pattern and then it's set in your mind. If you never know when the next "beat" is coming you feel anticipation; your mind is racing trying to figure it out. So you don't have to move your body fast at all. The same way a scary movie (if you are scared) isn't boring; your mind is whats moving fast, not the scenes.
Traveling- another way to show "fast" I believe is the idea of progress and moving forward. Like if you watch someone make a lifetime of accomplishments but it only takes them one year you will logically think they are faster. There's no way he's going to move that much faster physically but he might mentally. So while the other person is lets say building up to it, making mistakes, and reworking the same problem, he gets it done in 1 try then he moves onto something else, something different. Even though it takes him less moves, I believe the audience will read that as "faster" because they will imagine what you did in your mind to get there that fast.
You know like in scary films how even though the person being chased is running for their life, the killer somehow appears behind them and not even out of breath? It's basically like that: If you had to go from a--->b--->c--->d and in the time it took you to do that the other person found a way to get there before you logically you would think he is "faster" even if you never saw them physically run and it takes him less moves. This works because it forces the audience to put the 2+2 together so they are the ones working faster mentally, which will give them the feeling of catching up, which will make you seem faster.
Getting a Head Start- conceptually that is. It's similar to the one before this but pertaining more to everyone's personal skill level; kinda like the early bird gets the worm type deal. If you went to a market early, you would be the one to get the freshest fruits and veggies. By waking up early you are already out the door before everyone else has brushed their teeth. So it's more of a comparison between you and your surroundings but it works in a song as well. A song has its own "morning" and "night" sort of like a day. Starting your ideas early on will get you to those ideas earlier and without rush.
Have a Good Day!