SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f809301c574076fc7eed27fd9063c534b0bcc656a14b3bf0744808624d9a398' 
  AND token = 'B6j+UnGkc7ti381ujK9RUdZglBEYn5XgQxvkFq6By+4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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