SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c88f72086abcfcea586b85f1d013953203e7f72f21dab3bc7661e9335a48600' 
  AND token = 'l5WSkFx/7bwtc4VfD1RFeQMqhuIvRqfDiqkQDdNz7Ok=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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