SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9cc02ac117568abd2ae4c742b4727e570491515861d99933cdba7ff85d260ec4' 
  AND token = 'mFp/l4NKmrrytcWCIPeuWZBFNaAxlwQdWbomYuRZMr0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}