Looking to use a dropdown and checkbox in the same search field

I am attempting to create a search based off multiple categories. The user should be able to select all that apply. They do not need to select one from every category.

One of the issues I am having is that one of the categories is location. Location will have 50+ options, so a dropdown would be ideal. However, it is inconsistent with the rest of the options that include checkboxes. The checkbox categories will have 5-15 options. Does this design still work and will the user understand that they do not have to choose a location? What are some other options that might be better?

Also, what is the best way of aligning these categories?

Thanks in advance!