SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfedcaea518b1ecd87123b7b327bbd3d1e212b5017d1d8c9cfc01f182750e484' 
  AND token = 'lNpjrgJe6lDi8wAYvXQEeD4ZJPhtzXaqo/WwYlRvGxE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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