SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c511d4115917f57d1bace5c34e500336fea202c49013c15a15bb238177e728b1' 
  AND token = 'rM32m1WuT624CL+wBt4cxjnW3SpldykK/W3ohVAmigA=' 
  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