SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e308fd8d2f75f9bb26730ec16ba52d50004db34bdf93fe3d8ced5ac874d4b38' 
  AND token = 'dixy0ZLgF6kFOW/EnuUUde0L40Rr8y8PRI5JIgsnS4E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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