SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0b943b442fd2546345b5c70884444a76bbf98a16a250e938efc52a52a94dede' 
  AND token = 'AC9UHycFpchDR3euA/0N2HcoMTYNzWfLDb/giHjUMLs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

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