SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '8bf995b8c6641d06513961bdde932e6df00d1da49032a7b87f9b8ee28a460643' 
  AND token = 'FCmlzEzO2v95RAdFsncTX9F13xim7iL6ZGOPk9py5FQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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