5550'XOR(555*if(now()=sysdate(),sleep(45.622),0))XOR'Z

What you posted looks like a time-based blind SQL injection payload, obfuscated to try to slip past filters.

High-level breakdown (conceptual):

• The inner part: if(now()=sysdate(), sleep(45.622), 0)
  • In MySQL, NOW() and SYSDATE() are time-related functions. The condition now() = sysdate() is only true if the two timestamps happen to match at evaluation time.
  • If the condition is true, the sleep(45.622) call pauses the database server for about 45.6 seconds.
  • If false, it just returns 0.
• The 555* before the if and the multiplication by 555 after the IF are just to affect the value and, in practice, don’t change the delay effect (sleep returns 0, so the arithmetic yields 0 either way). The important part is the side effect (the sleep).
• The surrounding 5550'XOR( ... )XOR'Z is typical obfuscation to try to break out of a string context in an application’s query and to bypass simple filters. XOR here is a MySQL bitwise operator; the payload is crafted to fit into a string literal in a vulnerable query.

Implications:

• If this is injected into a vulnerable query (for example, where user-supplied input is concatenated into SQL), an attacker could cause a controlled delay to infer true/false conditions (time-based blind SQL injection).
• This is a common technique for detecting or exfiltrating data when there is no visible error output.

Defenses and safe practices:

• Use prepared statements / parameterized queries everywhere; never concatenate user input into SQL strings.
• Validate and sanitize inputs, and enforce strict typing (e.g., numeric fields should be numeric).
• Apply least privilege for the app’s database user (read/write permissions only where needed).
• Implement input validation that rejects unusual tokens, length, or control characters.
• Consider a web application firewall (WAF) and monitoring for anomalous long-running queries.
• Enforce timeouts on the database driver or at the application level to prevent long sleeps from affecting user experience.
• Use test-only, controlled environments (DVWA/WebGoat or similar) to study these attacks ethically and legally.

If you’re studying for an exam:

• Know what time-based blind injections are and why SLEEP() is used in MySQL.
• Be able to explain why NOW() vs SYSDATE() is used in such payloads and why the condition is often unreliable in practice.
• Be able to describe mitigations and safe coding practices to prevent such attacks.

Note: Do not test or deploy this against systems you don’t own or have explicit permission to test. It’s illegal and harmful to probe real environments without authorization.