SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de4e77960bd6a9d1e76957fe58ce889396c9354142cea0b8b861b1535369a629' 
  AND token = 'q3LL11hIS64y5WVcB2FsVg86OFI3a6lE4BfEjiE9O3E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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