The table below on this page lists how much experience you get if you blitz to a certain level and then stop.
As you can see, the deeper you go, the most experience you have to expend to get each new Crypt Token
The obvious trick here is to only blitz down to level 5 or level 10 and then quit. You won't get very many Crypt Tokens each day but if you're patient, you can eventually collect enough Crypt Tokens to get a higher-level Legendary Set without so many level-ups.
Another really important technique for getting Crypt Tokens is the VIP wheel. If you have VIP, wait until you have at least 36 VIP Tokens and then go the VIP Wheel. Just keep Refreshing until you see 30 Crypt Tokens TWICE. If you see that, you'll get 30 Crypt Tokens when you do a full run. If you're really lucky, you might hit 30, 30, and 10 crypt tokens all at once; if so, you'll get 40 crypt tokens for the run!
Using the VIP Wheel to get crypt tokens requires patience and a tolerance for tedium. Sometimes the two 30-token symbols come up after a few refreshes, but there have been times when I would spend 20 minutes or more refreshing, refreshing, refreshing. But, take heart, so for me it has not failed to show up eventually. You just have to believe it will come along and keep on clicking until it does! It's tedious but it's a way to Crypt Tokens with zero experience!
Experience Cost Per Crypt Token