SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c895d5a2c47d79762aeff303f0e8202f175bcc9307d1a3854b79a71256a7123' 
  AND token = 'KLd3N7k5Yr/oBGw7QhvgBavm7Mf1VgTZiiR+qTXxmAg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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