Depends on your carb tolerance.
Crackers are on the carb list, so in theory should be avoided.
Smearing them with a lot of butter helps to reduce the 'badness'.
Look at the percentage carbohydrate on the packaging.
I always struggle when I think of having 'just a little' of something which is 'not too bad'.
For me, it is better to just stay away from grain based products.
[Oh, apart from single malt whisky of course, and I break the general rules by drinking beer.]
Is there something else you can eat your cheese with?
Nice cool slice of cucumber?
I am not sure how bad an apple is compared to a cracker but I do have the occasional apple with cheese.
"An apple without the cheese is like a kiss without the squeeze."
So the answer is - O.K. is different for different folks, eat to your meter, but a nice piece of cheese on its own is a really good protein snack and you don't really need the cracker (although crackers, like so many other 'bad' things, are really nice with cheese).
Not really that much help, was it?
Cheers
LGC