SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9876a28a3f322ebec650132383be0ad67b13a456c7b9adf61167dd8aa9d915bc' 
  AND token = 'bQgkFP+Fte0uKxwl9sriHzWaa388Cmx84WWds0CrVvc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

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