Refresh tokens stored as UUID or JWT?

I'm creating a refresh token endpoint in my backend using spring boot, and I have a few questions. What's better when creating refresh tokens, should they be a JWT or a simple UUID will suffice?

For example, if I use UUID to generate a refresh token, in my refresh_token table, I would have expiry date, the user who generated that refresh token and of course the random UUID.

public RefreshToken createRefreshToken(Long userId) {
    RefreshToken refreshToken = new RefreshToken();

    refreshToken.setUser(userRepository.findById(userId).get());
    refreshToken.setExpiryDate(Instant.now().plusMillis(refreshTokenDurationMs));
    refreshToken.setToken(UUID.randomUUID().toString());

    refreshToken = refreshTokenRepository.save(refreshToken);
    return refreshToken;
  }

That was my initial implementation, but now I'm thinking isn't it better to create a refresh token as a JWT and have the payload contain the expiry date which mean one less read to the database when validating if a refresh token is not expired? And in the case I store my refresh token jwt, should it be hashed in the database when storing?

Here's a quick method I came up with

private String createRefreshToken(String subject) {
    Instant now = Instant.now();
    JwtClaimsSet claimsSet = JwtClaimsSet.builder()
            .issuer(JWT_ISSUER)
            .issuedAt(now)
            .expiresAt(now.plusSeconds(JWT_REFRESH_TOKEN_EXPIRY))
            .subject(subject)
            .build();

    return jwtEncoder.encode(JwtEncoderParameters.from(claimsSet)).getTokenValue();
}

Which method is better / more secure? Also, maybe a mini question, how can I retrieve the claims expiration when using JWT? I'm using org.springframework.security.oauth2.jwt in my controller?

Thank you!