SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc35e14b84cde38fb1ba8aec9d1ad02cf7f05937d939112158878222bc778593' 
  AND token = 'JF0LTk/SWYFSw2/p3itTW2caG7ss+wjmO/cwz2n1icw=' 
  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