SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf9639d77c691826fdaa44d966147e467fb3fee44cb988afa3484b7d5128d468' 
  AND token = 'wPx8Zd/0YdlWdRr9dXI6mEQgr+9wsUvjVBLuszz6Fbg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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