Since the last git build, you can do search like:

artist=eric clapton album=unplugged

It is still tokenized.  so artist=eric clapton matches not only the artist eric clapton but also clapton, eric.

You can stop tokenizing still in the same way: artist=(eric clapton).

I will add this to the normal search too:

Offcourse a screenshot:

Next release is going to be treat.

p.s. latest windows build now here