SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4532fbebcf60749a26819b8ada36d17a4b9890c6f7a124a3cd246cb64cbcd11' 
  AND token = '5VW1B4HhQQttrxyGo+RDl8Lo0GPGoKUTsCzyWYjJJTs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

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