title: Rails ActiveRecord type constraint
body: <p>I have the following model in a rails App
  <code>class Banking::PaymentToken &lt; Banking::Token (which is ActiveRecord)</code></p>
  
  <p>Banking::PaymentToken.find() include the following SQL constraint? </p>
  
  <p><code>"WHERE payment_tokens.type IN ('Banking::PaymentToken')"</code></p>
  
  <p>I want to add constraints <code>"WHERE payment_tokens.type IN ('Banking::PaymentToken', 'other_type')"</code></p>