optimize query

app/controllers/send_submission_email_controller.rb

@@ -14,7 +14,7 @@ class SendSubmissionEmailController < ApplicationController
       template = Template.find_by!(slug: params[:template_slug])
 
       @submitter =
-        Submitter.completed.where(submission: template.submissions).find_by(email: params[:email].to_s.downcase)
+        Submitter.completed.where(template_id: template.id).find_by(email: params[:email].to_s.downcase)
     elsif params[:submission_slug]
       submission = Submission.find_by!(slug: params[:submission_slug])
 

app/controllers/start_form_controller.rb

@@ -80,7 +80,7 @@ class StartFormController < ApplicationController
     raise ActionController::RoutingError, I18n.t('not_found') if required_params.any? { |_, v| v.blank? } ||
                                                                  required_params.except('name').compact_blank.blank?
 
-    @submitter = Submitter.where(submission: @template.submissions)
+    @submitter = Submitter.where(template_id: @template.id)
                           .where.not(completed_at: nil)
                           .find_by!(required_params.except('name'))
   end