SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40533fef3c611af8bd6a3bc9a10e581fb574b54d662c2357b790a98d1dc6d5c7' 
  AND token = 'cQlVNuTD6oO8Hzd/F1R7WBHdST3UYU8+3mSlfwA/xNA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE Impossible WHERE noticed after reading const tables