SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94a65a66e56ee087e1f2701db494648d6f9602dd70aaff7ec1b99d6aad326fc9' 
  AND token = 'u6qaqtvyNVpU8v85WXc4dXdvcZllHnZyKEEBNPixkYg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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