var arr =
[
    {
        "TokenID":"1",
        "USR":"Andrey Homez",
        "mensaje":"Hi :)",
        "date":"2017-01-17 02:52:52"
    },
    {
        "TokenID":"2",
        "USR":"Andrey Homez",
        "mensaje":"Hey!",
        "date":"2017-01-17 02:53:22"
    },
    {
        "TokenID":"1",
        "USR":"Paola Gonzales",
        "mensaje":"Hola!",
        "date":"2017-01-17 02:52:52"
    }
]

arr =
[
    {
        "TokenID":"1",
        "USR":"Andrey Homez",
        "mensaje":"Hi :)",
        "date":"2017-01-17 02:52:52"
    },
    {
        "TokenID":"2",
        "USR":"Andrey Homez",
        "mensaje":"Hey!",
        "date":"2017-01-17 02:53:22"
    }
]

function distinct(array,indice){
}

distinct(array,"TokenID");