This sounds a bit weird, maybe we can improve it a little.
"live today who knows whether you will be able to see tomorrow"
Still weird, but more understandable.
You may make some other changes to get that better from the original.
Perhaps the best way to say that doesn't match the original, but in my opinion, it would be:
"live the present day...who knows whether you will be able to live (see) the next"