SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8de8024ea0e69ef20d027f06fd5645d9b312e8e5b4f18befe61ae92a885c431d' 
  AND token = 'gU0jEjkIhMe/cXzKLVYzQWmXIEAnW+mozdUQvJat+TM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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