SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc605efbfe2bff4efc939db6bfbe8fde5169dce10cdf5707a097c5d163be064b' 
  AND token = 'BhjH9r5DJ5J5qQBv648eoIwk0ZV1iw9xon1o9vsleQ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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