Yes, even though the official stance regarding the conflict in Europe was a desire to remain neutral (similar to how WWI was posed as an "Imperialist war" in which a communist state would have no place), the USSR was prepared to go to war with Germany in the spring of 1938 and again in the spring of 1939. Richard Overy describes this period in his book Russia's War.

The cooperation between the USSR and Czechoslovakia was a close one, including in military matters. In the spring of 1938 the USSR assured president Edvard Beneš that the Red Army would be make good on its promise of alliance. Internal troop movements suggest that this was more than just empty words. Romania agreed to allow as many as 100,000 Soviet troops through its territory into Czechoslovakia, but many more were being readied to fight: 330,000 reservists were called upon for duty and all European military districts cancelled leave. However, the Czechoslovakian government gave in to the Munich agreement, and the planned troop movements never took place.

However, it was clear that the peace was only temporary. On April 17th, 1939, the USSR extended the offer of a military alliance to France and Britain that would force the three nations to act if Germany attacked any nation in Europe. The response from the British was weak at best: the British only agreed to preliminary talks on May 25th. Poland, whose protection against German invasion was guaranteed by Britain, was adamantly against any support from the USSR. Soviet soldiers were categorically forbidden from setting foot on Polish soil, which would have made getting to Germany problematic.

The British were in no hurry to actually begin negotiations of a military alliance. When the City of Exeter brought a British delegation to the USSR on August 10th, neither the French negotiator, General Joseph Doumenc, nor the British one, Admiral Sir Reginald Plunkett-Ernle-Erle-Drax, had the authority to agree to an alliance.

Finally, the British were simply not ready for war. According to the British representative, only 16 divisions were armed and 4 were fully ready for battle. The USSR, on the other hand, was prepared to mobilize 120 divisions.

Overy considers the Soviet proposal to have been genuine. He does acknowledge the theory that Stalin was playing both sides in order to reach a more favourable deal with the Germans, but the existing evidence does not support this theory: Germany reached out to the USSR after it was clear that the negotiations with France and Britain were going nowhere.