SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69dbea486c1f96a6d101963a6f2b3646349f83f93bd6198ded78b67ab53e1790' 
  AND token = 'L8bf9CQNKQp0WROwit1Dg9Pn8pZ+Wva1tswe7ZWPgQ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

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