Something that's hokey is silly and sentimental — you could also call it "sappy" or "mawkish." A hokey speech is more likely to make people roll their eyes and squirm than to make them cry.
You can buy your friend a hokey birthday card as a joke, or read her a hokey poem to make her laugh. There's a hint of insincerity when something's hokey — people can tell that the sentiments in your hokey yearbook quote aren't entirely genuine. In the mid-1800s, hokey-pokey was defined as "false, cheap material," possibly based on hocus-pocus, and usually referring to artificial flavoring in cheap ice cream. Today, the hokey-pokey is mainly known as a silly dance.