**Expected behavior**

When using `getrawtransaction` with an included `blockhash`, performance should be better as there is no need to scan the entire txindex.

**Actual behavior**

Running `getrawtransaction`  while including the `blockhash` is ~5x slower.

<!--- What was the actual behavior (provide screenshots if the issue is GUI-related)? -->

**To reproduce**

```
$ time ./bin/bitcoin-cli getrawtransaction 20a93350cd6f4e03dfb6cbb3f104965293627f25c199c1be0e4d187a4ed5f4bb
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

real	0m0.003s
user	0m0.000s
sys	0m0.002s
$ time ./bin/bitcoin-cli getrawtransaction 20a93350cd6f4e03dfb6cbb3f104965293627f25c199c1be0e4d187a4ed5f4bb false 0000000000000000000a801776a92ced69dc5fb0a5919271872a9261a613d9c3
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

real	0m0.014s
user	0m0.000s
sys	0m0.002s
```

**System information**

GCP c2-standard-4 (4 vCPUs, 16 GB memory) with 1TB of persistent SSD

Ubuntu 20.04.2 LTS
Bitcoin Core v0.21.1
{
    return RPCHelpMan{"signrawtransactionwithkey",
                "\nSign inputs for raw transaction (serialized, hex-encoded).\n"
                "The second argument is an array of base58-encoded private\n"
                "keys that will be the only keys used to sign the transaction.\n"
                "The third optional argument (may be null) is an array of previous transaction outputs that\n"
                "this transaction depends on but may not yet be in the block chain.\n",
                {
                    {"hexstring", RPCArg::Type::STR, RPCArg::Optional::NO, "The transaction hex string"},
                    {"privkeys", RPCArg::Type::ARR, RPCArg::Optional::NO, "The base58-encoded private keys for signing",
                        {
                            {"privatekey", RPCArg::Type::STR_HEX, RPCArg::Optional::OMITTED, "private key in base58-encoding"},
                        },
                        },
                    {"prevtxs", RPCArg::Type::ARR, RPCArg::Optional::OMITTED_NAMED_ARG, "The previous dependent transaction outputs",
                        {
                            {"", RPCArg::Type::OBJ, RPCArg::Optional::OMITTED, "",
                                {
                                    {"txid", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "The transaction id"},
                                    {"vout", RPCArg::Type::NUM, RPCArg::Optional::NO, "The output number"},
                                    {"scriptPubKey", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "script key"},
                                    {"redeemScript", RPCArg::Type::STR_HEX, RPCArg::Optional::OMITTED, "(required for P2SH) redeem script"},
                                    {"witnessScript", RPCArg::Type::STR_HEX, RPCArg::Optional::OMITTED, "(required for P2WSH or P2SH-P2WSH) witness script"},
                                    {"amount", RPCArg::Type::AMOUNT, RPCArg::Optional::OMITTED, "(required for Segwit inputs) the amount spent"},
                                },
                                },
                        },
                        },