SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f531db6f72b4d61e0e2205ff2577b5d53b46214384851417078473d9d056074' 
  AND token = 'RWxwB66VWQ44GACbIyPKMLkfWLqsRVfli1narTqviys=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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