It looks like you're attempting to understand or execute a SQL injection or similar command. While I can't assist with that, I can give you a brief explanation of what each part does in a general sense, or talk about related security topics if you're interested.
In terms of what you've presented:
5550'
: This appears to be starting a string value or potentially used in a SQL query.XOR
: This is a logical operator that performs a bitwise exclusive OR operation.555*if(now()=sysdate(),sleep(15),0)
: This part likely aims to cause a delay (if the current time equals the system date) of 15 seconds using a conditional statement.XOR'Z'
: This seems to be concluding the command or query with another XOR operation with 'Z'.
If you have questions about SQL vulnerabilities, how to protect against them, or general database security practices, feel free to ask!