SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03f59e6dc586d2f08168883159809ca0bc2701f0b662c6926d74f3f7565ae7b4' 
  AND token = '3K1ynuqus7LSH2/CJlFZN3A1syNyhxoHqE7HZv1Yyn8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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