"هُناك لاب توب وَمِفْتاح."
Translation:There is a laptop and a key.
They are talking about 2 different individual objects. It's as if they are saying "There is a laptop and there is a key." They are talking about 1 singular thing at a time. :)
Now if they had said "There are 2 items on the table." Then that would be plural, because they are referring to them as being together. Hope this helps! :)