AWS RDS is not connecting with laravel ec2 intance

I have create laravel rds mysql database but not that rds database is not connecting with ec2 instance laravel project . it is giving this error

 SQLSTATE[HY000] [2002] Connection timed out (SQL: select * from information_schema.tables where table_schema = asfalconsd and table_name = migrations and table_type = 'BASE TABLE')

  at vendor/laravel/framework/src/Illuminate/Database/Connection.php:671
    667|         // If an exception occurs when attempting to run a query, we'll format the error
    668|         // message to include the bindings with SQL, which will make this exception a
    669|         // lot more helpful to the developer instead of just the database's errors.
    670|         catch (Exception $e) {
  > 671|             throw new QueryException(
    672|                 $query, $this->prepareBindings($bindings), $e
    673|             );
    674|         }
    675|

      +36 vendor frames
  37  artisan:37
      Illuminate\Foundation\Console\Kernel::handle()

I have gave credentials in env file but still i think there is any kind of configuration is missing . May be Inboud rule etc but i dont know how to set it up

via Chebli Mohamed