Yes, BOXWOOD is a Scrabble word!

Letter values in Scrabble US: B 3, O 1, X 8, W 4, O 1, O 1, D 2.

Is it a valid word?

BOXWOOD is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

very hard tough close-grained light yellow wood of the box (particularly the common box); used in delicate woodwork: musical instruments and inlays and engraving blocks
evergreen shrubs or small trees

Also: turkish boxwood.