SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3e9549b8aa63f23355bc5368ccf238b9f47c400974ccdd8c07af88897a87e881' 
  AND token = 'VvQxc0KgyGUVg73IrqDYpaCm+XZn5VpyXonfwJ8gnXM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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