SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3995eb8a4d40fbf74a1ed9812039e62fe3fac69cb6a43e1b51910f9d81970b34' 
  AND token = 'aGCDXACzFKh1jRCvuhSfu4AowsLY+nLzxYWoK7Fj5nY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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