Refactor the code

How can i refactor the below code

class BlogPostsController < ApplicationController
  def ex
    @p_p = B.where(‘published_at <= ?’, Time.now)
    @unp_p = BlogPost.where(‘published_at = ? OR published_at > ?’, nil,
Time.now)
  end
end

How would I optimize the following code?

and

How can i refactor the below code

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towards actual enlightenment rather than a plagiarized solution.