No, not here. We're really asking if salt is "inside" the finished product that is bread or cheese, and that would be "contain" -- in the same way, for example, that a cup might "contain" tea or coffee. If you were specifically asking about the list of ingredients used to make the bread or cheese, then "include" would work.
I'm native AmE, and I can think of at least three common ways of asking this in English: Is there salt in bread and cheese? - Do bread and cheese have salt in them? - Do bread and cheese contain salt? Which of them is used more often may be a matter of regional usage or personal preference. But I would suggest that (a) since we are learning Czech, this exercise teaches us that obsahovat means "to contain"; and (b) the last one is definitely closest to the Czech sentence.