"unique key" token is not highlighted

[Orionsg]

Example:

create table country
    (   id              smallint unsigned   not null    primary key     auto_increment
    ,   name            varchar(100)        not null    
    ,   iso_2           varchar(2)          not null
    ,   iso_3           varchar(3)          not null
    ,   unique key      ux_ctry_iso_2       (iso_2)
    ,   unique key      ux_ctry_iso_3       (iso_3)
    ,   unique key      ux_ctry_name        (name)
    );