SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40214c7a3906c6e4cd32daf507ef460b8ac4d1bb549710853d283d4bd1097db6' 
  AND token = 'ucXc7STXHmsJSrIuttFKqUw6Id+/EG/cOMqXBdjmHbM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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