SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f7c7868c405109951c92a42b6d883d680b16d5600663fc5bb1103c7adf63721' 
  AND token = 'utIE2cm4NSXjzRHC3gpLVxL4GNKUt9BPma6lR6VJj/E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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