Stone of the quay or wharf
A modern variation of the English surname Keystone, likely referring to a stone used in the construction of a quay or wharf. It may also be associated with the architectural 'keystone', the central wedge-shaped stone at the summit of an arch that holds the other pieces in place.
Less common today
Keyston isn't in the latest US Top 1000. It last peaked at #7,894 in 2013.
US births per 5-year period, 1990βpresent (SSA data).