45.7 billion light-years is the current comoving distance to the edge of the visible universe - this distance includes expansion. It is the distance now, not the distance when the light we are seeing was emitted. The observable universe was smaller when the light we are seeing now was emitted, because that light has taken time to reach us.

The light being emitted now from objects at the edge of the observable universe will not reach us for a very, very long time - much longer than 45 billion years, because the space in between us and that light will expand even more while it is traveling. Light traveling from 45 billion light years away will have to travel further than 45 billion light years to reach us.