SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc84073ffb0b5ef3ea6afd76b5e0e17795644e9d1d6536ae757b271a59fe33eb' 
  AND token = 'ikRYlnoC4F5+ZCdTzTFQMY3pQQ7tI/akGE8WERzCYcM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}