The only way was to create a new class and explicitly specify constraints by overriding GetCell method:
public class BaseEntryElement:EntryElement
{
.....
public override UITableViewCell GetCell (UITableView tv)
{
var c= base.GetCell (tv);
c.ContentView.SubviewsDoNotTranslateAutoresizingMaskIntoConstraints ();
c.ContentView.AddConstraints (
c.ContentView.Subviews[0].WithSameCenterY(c.ContentView),
c.ContentView.Subviews[0].AtLeftOf(c.ContentView,BaseEntryElement.offset),
c.ContentView.Subviews[0].AtTopOf(c.ContentView),
c.ContentView.Subviews[1].ToRightOf(c.ContentView.Subviews[0],40),
c.ContentView.Subviews[1].WithSameCenterY(c.ContentView.Subviews[0])
);
return c;
}
}