SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23d409e60805ebfee2607fc6c21e33456124c9cb0c39d36f05528f0e74d23e34' 
  AND token = 'TDPVqT12C1gzAJw+fMeTPJjHmU3b2cuA4u4RJAGeSwE=' 
  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