SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '02f5b8ef9f0207c4626053fc179d68f043bb455a5e0a5a0ba996e33d984020ea' 
  AND token = 'q1fTU+rFFCDNTiHUjSPoipdwfQK9t6TIoIhgP/5fFvY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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