Django: Set foreign key using integer?

Is there a way to set foreign key relationship using the integer id of a model? This would be for optimization purposes.

For example, suppose I have an Employee model:

class Employee(models.Model):
  first_name = models.CharField(max_length=100)
  last_name = models.CharField(max_length=100)
  type = models.ForeignKey('EmployeeType')

and

EmployeeType(models.Model):
  type = models.CharField(max_length=100)

I want the flexibility of having unlimited employee types, but in the deployed application there will likely be only a single type so I'm wondering if there is a way to hardcode the id and set the relationship this way. This way I can avoid a db call to get the EmployeeType object first.