Its from a 1890s secretary drawer. The shape is reminiscent of a warded key, except it has this pin at the top that I have never seen in a lock. The key would have to have a corresponding hole, which no modern warded key I know of has.
Where can I get a key like this and what is it called?
I don't think it is, the secretary has other key holes with the same pin. The only difference is that this one also has this warded-lock-type shape