SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41edcf2336a10e71b450109fd0e5c21ce768aa1c0c9cd09f5fa37535b3a5ac7e' 
  AND token = 'MFDNSzje4+gQ2M2su2UTue5Sy/0gx9Mo96bwZBy33Zo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

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