SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'a314f5ce37ea7bedcdbd02bd700f2ef398c0d65d0497f18ab8afa4b6ead782da' 
  AND token = 'BAloiwxKtoBat8NKmkBzWEpFcCIuGyuM5wQrUeRd6Gs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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