How to open a new blank document in Pages from spotlight?
Part of the problem can be eliminated by selecting a default template in the Preferences.



Then, when opening from Spotlight or Alfred, a click on the new document button opens your default template.  [Blank in the case of the setting shown above.]

Then, one could create an Automator or Applescript workflow that is attached to a service evoked by a keystroke combination.



Edit: OP @Rusl added this Applescript to a keystroke combination.

tell application "Pages"
  activate
  make new document
end tell