Catalyzes the liberation of alpha-xylose from the non-reducing terminal glucose of xyloglucan oligosaccharides. Hydrolysis of terminal, non-reducing alpha-D-xylose residues with release of alpha-D-xylose. Despite the presence of an amyR-binding consensus sequence in the promoter, is not activated by isomaltose. Belongs to the glycosyl hydrolase 31 family.