The CTK-573 has a "Tune" setting with a range of -50 cents to +50 cents; see page E-35 of the User's Guide.
If you don't have a copy of the User's Guide, you can download it from Casio's web site (see the link below)-- but note that they don't list the CTK-573, so you'll need to use the link for the CTK-571, as the User's Guide is for both the CTK-571 and the CTK-573.
The "Tune" setting affects the entire keyboard-- i.e., there's no option for scale-tuning, or tuning the individual notes of a scale based upon the base note of the desired musical key and some specific tuning system.
http://support.casio.com/en/manual/manual.php?cid=008
Click on "I agree" and use the link for the CTK-571.