SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd6e4a575de673d7938a0166487579747f81b7d11bafa7d06ec232c7295bf632' 
  AND token = 'YFUzMHGnRCAnLbZCuQd5vPA+caiPnvaVPUmsmKJzAIc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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