SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '57dcd46e82a9d804f317889d231612743c5f4ec06bbdab7e52a9fb77065e753b' 
  AND token = 'yEiHC0rEp1vj4V3iZoB9fiPd7qKvlqLBZGtWgOjAPME=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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