SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8bf2d76559a16514bdaa7a87a69219f858859099f10ba137a54b489b0f9fcde9' 
  AND token = 'oipu9uQ3ejaF1LaRw3wvK4/ZqARVMPKixz0kBAJsMfc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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