Lowest forward voltage Schottky diode
Low forward voltage inherently means a lot of reverse leakage, particularly at high temperature. So there's not much in the way of free lunch. 

If you only care about Vf at given current, pick a Schottky diode with the lowest voltage rating and highest current rating you can. For example, a 1N5817 has a typical Vf of 151mV at 1mA. There are surface-mount versions you can search for. 

That said, perhaps there is a better way of doing whatever it is you are trying to do.