Yes, CLAYS is a Scrabble word!

Letter values in Scrabble US: C 3, L 1, A 1, Y 4, S 1.

Is it a valid word?

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

a very fine-grained soil that is plastic when moist but hard when fired
water soaked soil; soft wet earth
United States general who commanded United States forces in Europe from 1945 to 1949 and who oversaw the Berlin airlift (1897-1978)
United States politician responsible for the Missouri Compromise between free and slave states (1777-1852)
the dead body of a human being

Also: lucius clay, lucius dubignon clay, henry clay, the great compromiser.