Yes it will affect the SEO. HTTPS is basically a secure communication form of HTTP. Every web
page has a URL on top bar. Google looks on these pages favorably. It does not index HTTPS pages only,
however it additionally recognizes HTTPS as a ranking indicator. HTTPS is must faster than the HTTP,
which can affect CTR (click-through rate). So yes, changing the HTTP to HTTPS should positively impact
on your overall rankings!