SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b1e1e3fd441356f21a716fbcd1ef0402ae71dd1f795169280672f6efd2ab2a47' 
  AND token = 'JmzmXt+Zd2PiSOq9GeXImnpiljoZfjdw4v6MkdFT1Fg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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