SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b1578672f1d2f1714157a23497ac842650c6d1caf2748d67add91c85a5ed0c1' 
  AND token = 'Jvj97/E90rhUuVNZQ43W8leKYIe+briCA1Q3MXTLLJk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}