ActiveRecord has a class method implicit_order_column= that allows you to override the behavior of the .first and .last methods.
class User < ApplicationRecord
self.implicit_order_column = "email"
end
User.first
User Load (3.2ms) SELECT "users".* FROM "users" ORDER BY "users"."email" ASC, "users"."id" ASC LIMIT $1 [["LIMIT", 1]]