Thank you @<1523701087100473344:profile|SuccessfulKoala55> for the ideas. AMI is - ami-0025f0db847eb6254 , it may doesn't have docker, yeah - I will check out that.
My main assumption is that AWS Autoscaler can't establish SSH connection with a EC2 instance. Because the EC2 instance is created without public IP address (not sure if it's the clue).