SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3676f67f6688acb5106e774dc3371be16575579177eedc16b08b4bddab011124' 
  AND token = 'ZmKEZDvpWNlrUBwKGO7mps+idVqcwP7rqQbJYBxNefU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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