SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e15f57626a35f3d6ba783943f7d40d17fae1bc235bb10f09ea478d8648417ab' 
  AND token = 'fbBicFGDAdSOk8YodiamiXOrHpZSV+4qF5CmTaS/Inw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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