SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6280003a836148c2f209fdd24644856cf2c2053fdc86c7aa8eb8f8bfad866e1' 
  AND token = '4M59FqVGi7DBkRUlT0rLw9mLWp6hY3lEo4TQJ+U1sYg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

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