SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a6df9ab8f103d38ec76d58f3c029f7bd080a5a0def5979bcd73c4e7763e86c6' 
  AND token = 'Kky3BH50jbBZn/t2TtksBb+e7B55ouqcTifomtKaBpM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

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