SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '172168f01d52d75cc6592867c82264bc66f586c9936974843fd351365c53728a' 
  AND token = 'dueXDVedP7dQH/jofZAAGwcTSpAEH5XyydZfUoOnucw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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