SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6ef09d59f15afc7ab3306c7688f7e09277abbfe19dd28cec9e7fd83888ab1768' 
  AND token = 'Knhz1EcXnjhVNPrfXxkC3TZ/33FRNe0vxKx90BBevdI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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