Hi Martin,

We don't offer theme customizations but I will try to help you this time.

Can you please add the code below to Custom CSS

.menu-cart-icon-container .lab-wc-mini-cart-contents {
    -webkit-transition: all 50ms cubic-bezier(.445,.05,.55,.95) !important;
    transition: all 50ms cubic-bezier(.445,.05,.55,.95) !important;
}

If you still think that the animation is slow, you can add this CSS code too:

.menu-cart-icon-container.open.menu-cart-icon-container .lab-wc-mini-cart-contents {
    -webkit-transition-duration: .2s !important;
    transition-duration: .2s !important;
}

Will set this ticket as solved from here.