SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f853c521e6999e830d3ccf6edbeaeea85545c7ae6bd251324b297de84214bea5' 
  AND token = '9ojDePyNtcmBcIhZ/umCxj0+RJvJ59oozgYOYGes6RQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

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