SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17e7792554c05a448e075171a42348443876361b30ffed4bd270d3d4804bd923' 
  AND token = '2JqNDR9NyQiQkFQtjvEQutYmqpdChb6Ct0LgiD3xtn8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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