SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c361d328a8b5461b8d2233e0316467af97494a105271dde249ddcaeadec7310' 
  AND token = 'YodIMks8fY2neXvJuIH3if2qHOKaabP7Z7OyEheKtnQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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