SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'deb45ac9c26977b7b9dd3e62dc71eb7bef77ff3006f70d44a844841898847951' 
  AND token = 'va8ch+vBv30qD+fqOHjuQx3/UhL/IspRUw2znVp+Irg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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