Anti-Social: Acting in a way that shows disregard for others, with the potential to cause harm to others or society, either through intentional action or negligent action. (Persistent Anti-Social Behavior is part of the diagnosis for Anti-Social Personality Disorder)
Asocial: Lack of strong motivation to engage in social activities; a preference for solitary activities. (Severe asocial behavior that involves a lack of empathy or the lack of the ability to form intimate or close relationships is often observed in those with Schizophrenia)
If you do not feel like engaging in social activities because you don’t want to (as opposed to experiencing social anxiety and avoiding social activities because of that), and you prefer to keep to yourself or engage in activities that don’t necessitate interacting with others, and are fine with it, you are showing Asocial behavior.
If you care little, or not at all, for the rights of others or the rights of society, and because of this you actively, or through inaction, cause harm to others or to society itself, you are showing Anti-Social behavior.
These two terms are not interchangeable.
