Is it actually Harmonic Minor Mixolydian scale or is it called just "Spanish scale"?
If you are referring to the 5th mode of the harmonic minor scale, that scale is typically referred to as the Phrygian Dominant scale due to it being the Phrygian scale with one alteration that makes the tonic chord a dominant 7th. It does have other names one which is "Spanish Phrygian".
Built off of A, it would contain the following notes:
A B♭ C♯ D E F G