SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db3f40f90c73d7dfd0786a322df2fb3c6ae1a076df051dadce2670a70ca0da15' 
  AND token = 'LNHYdZ/8eOfoBpR/7yVeCTfWNwcqwK6ApJgM81STPCI=' 
  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