diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index 182460d4d8..ff9a368178 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,3 +1,7 @@
+*   Fixed the performance regression for `primary_keys` introduced MySQL 8.0.
+
+    *Hiroyuki Ishii*
+
 *   Add support for `belongs_to` to `has_many` inversing.
 
     *Gannon McGibbon*
diff --git a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
index 7737aa488d..c03def9106 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
@@ -433,11 +433,11 @@ module ActiveRecord
 
         query_values(<<~SQL, "SCHEMA")
           SELECT column_name
-          FROM information_schema.key_column_usage
-          WHERE constraint_name = 'PRIMARY'
+          FROM information_schema.statistics
+          WHERE index_name = 'PRIMARY'
             AND table_schema = #{scope[:schema]}
             AND table_name = #{scope[:name]}
-          ORDER BY ordinal_position
+          ORDER BY seq_in_index
         SQL
       end