SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ace1d2f076ca36d9bc555fc0adbeb67fafd7ccc7f1419216769ea1ff73a86e8f' 
  AND token = 'tUEsMW1+hiNudpSRNd1lE2owiDj1lSHfChfLWXZ83pY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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