I wouldn't recommend using this relay as you propose.
Even though contact ratings are expressed in volts and amps, they are not to be considered as an overall "power rating" as you suggest. Therefore, you cannot trade off voltage for current as you would in certain other devices (e.g. a power transformer).
The reason is that the voltage rating of a pair of contacts is determined by one set of parameters, while their current rating is determined by another set of parameters.
The voltage rating is primarily set by the distance between the contact's actual contacting surfaces while the contacts are in the fully open position. This distance prevents the applied voltage from directly arcing thru the air space between them. Further, the conductive members which carry the voltage to the contacts must also be kept a safe distance apart throughout their paths within the relay structure, and from the relay's coil windings & coil terminals in order to prevent arcing between these various elements, which may or may not be fully or partially insulated.
On the other hand the current rating of the contacts is determined by the diameter and thickness of the contacts and their conducting members. A larger current rating requires larger diameter and thicker contacts. The metal the contacting surfaces are made of is also important. Some materials are superior for certain ranges of currents than others. The shape of the contact matters too. This minimizes arcing when an inductive load is switched. Contact materials are often different for AC & DC loads, as well as for the range of expected load and switching currents.
Choose your relay carefully and conservatively and it will provide long and reliable service.