You got yourself a real problem there. Not much you can do to make it look planned. Toe kicks are usually 4" high, and 3" deep. From looking at the picture the base looks like it sits ahead of the stile, which is flush with the wall.
That type of offset is very difficult to work around. Personally, that offset would be a continuous source of irritation to me. I would cut the base to fit under the toe kick, and miter, and return it to the toe kick of the cabinet.
If it has to sit as it is, cut what's called a "self-edge", which is basically a very narrow return made by a miter leaving the waste piece the width of the base. attach the mitered piece to a mitered edge on the base, and the straight cut on the waste piece sits on the wall and finishes at the right edge of the stile.