It’s a psychological trick. The further the expiration date, the more valuable the offer appears. Sellers know that by the time 2030 arrives:
Many sites that offer "free keys" require you to download a "keygen" or "activator." These files are frequently injected with the very Trojans and spyware you are trying to avoid.
These are often volume licenses meant for businesses. Once Avast detects they are being used publicly, the key is blacklisted and your protection stops.
If you browse through tech forums or "crack" websites, you will often see claims of Avast Premium Security activation codes that last for decades. In reality, these are almost never legitimate retail keys.
A license key valid until 2050 would cover nearly 30 years of software updates, threat definition updates, and technical support. From a business perspective, this makes zero sense for Avast. Software companies rely on recurring revenue to fund their research, development, and global threat monitoring.
A quick search on e-commerce marketplaces, social media, or forum sites reveals dozens of sellers listing "Avast Premium Security license key valid until 2050." Prices range from as low as $5 to $30—a fraction of the official annual subscription (typically $69.99–$99.99 per year).