SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b0d5496e3350442082480674142671380a9bf4a0828197bc647461e7ec3bb02' 
  AND token = 'TXgO3PGr+2OmOyy6ZUqH0EBrJVrnp8xunBac8m+YtgI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

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