SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '04c87280cb30ceef3c585050cc65861481188557759b9430dba1c567a6ca3533' 
  AND token = 'DU3jmltXPmPSF//OHj4njzYx+nG6VYHRqsa9MYppDj8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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