This is clearer imo

app/models/card/entropy.rb

@@ -8,7 +8,7 @@ module Card::Entropy
     scope :entropic_by, ->(period_name) do
       left_outer_joins(collection: :entropy_configuration)
         .where("last_active_at <= DATETIME('now', '-' || COALESCE(entropy_configurations.#{period_name}, (?)) || ' seconds')",
-        Entropy::Configuration.default.to_sql)
+        Entropy::Configuration.where(id: Account.sole.default_entropy_configuration).limit(1).to_sql)
     end
 
     scope :stagnated, -> do

app/models/entropy/configuration.rb

@@ -1,5 +1,3 @@
 class Entropy::Configuration < ApplicationRecord
   belongs_to :container, polymorphic: true
-
-  scope :default, -> { where(container_type: "Account").limit(1) }
 end