SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ab38f5b86d6880c2819404a2417078351c8a5cd61099baffd8ad4c2ca3dd14d' 
  AND token = 'J+Y1gkbWvQbQcTpDKXpMvepmIo60zw5h4Xi0KuSSpw8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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