SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e8e71ded773cfcfc1dc22a11bbde47fcdedd73673ef752461a43d0bf1ae0315c' 
  AND token = 'sACnu4mJKqoUERZFFAqVWRHky9ge6zir1B/X7n1G9Ps=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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