SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73f8bab69796b44d46716952b44d5a9dbba00e7b842dc196e2b38b21e634752a' 
  AND token = 'hXPJZW7RKB0TpxlFR4SHvkZ6pYa6athrTOKrxWvMrHo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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