I'm going to guess that some/many of your cards have a high cognitive load - not just a question of recall, but perhaps solving a problem/proving a theorem. Or even stating a complex theorem can take time.
I solved this problem by having two separate decks. One that is purely quick recall, where if you know the answer you'll flip through the card in seconds. The other deck is the high cognitive load one, where it may take, say, a minute or longer for some cards.
I review the "quick" deck daily - it takes perhaps 5 minutes. It's hard to convince yourself you can't spare 5 minutes.
The other deck I do less frequently - perhaps target once a week, and block out time on your calendar for it?
I solved this problem by having two separate decks. One that is purely quick recall, where if you know the answer you'll flip through the card in seconds. The other deck is the high cognitive load one, where it may take, say, a minute or longer for some cards.
I review the "quick" deck daily - it takes perhaps 5 minutes. It's hard to convince yourself you can't spare 5 minutes.
The other deck I do less frequently - perhaps target once a week, and block out time on your calendar for it?