What about the ring of debris in geostationary orbit? Will that decay in 60M years?
Geostationary is only stationary in relation to a specific point on earth (geo). It just means it stays above a point on earth. It requires regular minor adjustments.
L1, L2, and L3 aren't stable. L4 and L5 are... but you would still need to adjust for the earth and moon not being perfect spheres; the moon moving slowly away from earth; tidal variations; solar wind; debris; etc.
L4 and L5 would last the longest, but not 60m years.
Someone else mentioned the objects we've placed on the moon. Seems to me that those would last the longest. The moon gets hit by small meteorites daily, but nothing that would destroy what's up there.