SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '57cfe707a19671633450101791292230f9f8593fa346ed67e9db1b7232014817' 
  AND token = 'MMWgtGOsb6Wy4+epuqIBW9jx9AjsBSfWdzZiou4YsdE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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