SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8fe6a7e9cdeab9e700dbe537f3caff2838d0947e27d5e83cab6c161e9d315794' 
  AND token = 'df+qonvC5t/5iAhIQwv+tgtLDR8n4oz1LZmt9rKBUyg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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