Praise be to Allah.
Prostration is one of the essential parts of the prayer, which is not valid without it, except in the case of one who is unable to prostrate because of sickness, or because he is being detained in an unclean (najis) place, in which case he should lean forward.
It says in Kashshaaf al-Qinaa‘ (1/351): The worshipper should prostrate on these seven parts of the body: the forehead, the two hands, the two knees and the two feet, along with the nose, and that is an essential part of the prayer when one is able to do it, because of the marfoo‘ report narrated by Ibn ‘Abbaas: “I have been commanded to prostrate on seven bones, on the forehead,” and he pointed to his nose, “the two hands, the two knees, and the edge [toes] of the two feet.” Agreed upon. And he said: “When one of you prostrates, seven parts of his body prostrate with him: his face, his two hands, his two knees, and his two feet.” Narrated by Muslim.
The hadith “My face has prostrated…” does not mean that you should not prostrate on other parts of the body. Rather the face is singled out for mention because the forehead is the most important part for prostration. If a person fails to prostrate on any of these parts, then his prostration is not valid.
If he is not able to prostrate on his forehead, he should lean forward as much as possible, and the obligation to prostrate on the other parts is waived, because the forehead is the most important part in prostration, and the others follow it. If the main part is waived, then the rest are also waived.
If he is able to prostrate on the forehead, the other parts mentioned follow it, because of what is quoted above. End quote.
It is not permissible to delay prayer until after its appointed time, unless one is putting the prayers together – Zuhr and ‘Asr, and Maghrib and ‘Isha’ – for a reason that makes it permissible to do so.
For information on such reasons, please see the answer to question no. 147381.
What you have mentioned about precautions to avoid infection is not an excuse for not prostrating or for putting the prayers together. You can keep a prayer mat and pray on it, and you can disinfect the side of it that touches the floor.
You can also keep with you a number of cheap plastic tablecloths or clean plastic bags, and offer each prayer on one of them, then throw it in the bin after you have finished praying. Thus you can protect yourself from any harm that may come from the floor, and also protect yourself against contagion.
And Allah knows best.