SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9da3eb805b6ce09649a612746823630244547a9e0abc16a012ead8cda263e2e' 
  AND token = 'NDWLVBTrXf95aTWCUS3wvatCtsQ1XhEM7CsgxNRzM7k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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