SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'c753f5ef23212f2b1eccf3d99847851dae4fcb1e2107aa7ba5a91bfb66b8b3ef' 
  AND token = 'y4EPtZN+UoCJw8KQR+gDm0oVqZYkbVhAa+Ba4p6ZocU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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