A few x values picked at random:
48, 197, 387, 394, 466, 825,
Primes for each of them:
3^48+10^10
3^197+10^18
3^387+10^44
(none found)
3^466+10^186
(still none)
But still, a higher chance that there is a prime of the form 3^x+10^y (y less than x) for any x value.
