#Try similar below code:

class MyTable(models.Model):
    class Meta:
        unique_together = (('key1', 'key2'),)

    key1 = models.IntegerField(primary_key=True)
    key2 = models.IntegerField()
#or if you want only unique mixed fields:

class MyTable(models.Model):
    class Meta:
        unique_together = (('key1', 'key2'),)

    key1 = models.IntegerField()
    key2 = models.IntegerField()