write a script to redirect link (base64 encode) and cache the decoded links

Hello, I need a simple script to redirect links (javascript, 301), link was encode base64 , the javascript option can redirect after x Seconds (show a page have a message with count down), cache the decoded links. is cache better for speedup ? (have timeout for cache). I don't need interface, I can config it manually, just tell me how for example: domain.com/redirect/aHR0cDovL2dvb2dsZS5jb20= [login to view URL] it will redirect to [login to view URL]