SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3619202b63577eab4de611f7018cca68492e410c534722659ea6f480132a9586' 
  AND token = '2SFzhvF5OxnQdvzvs5JZHQs9PrAyTEP2PUQ8HurC1Rc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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