SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'af3db64d0bceaeafc0c268ca9b06accfdab427cf89f9d7fd56e3a28db24fae87' 
  AND token = 'X4TkuLRy4eto1/YMbG3m1XD+zP7nAsaKKGNKt3S6mbU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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