SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1bb732fad2aa4bfb49c7c6044dd4ade72ccc716804fe074fcccf44db8b4caac' 
  AND token = 'kMH3ryY3Wf8UX3aFBwWQ59WtQsG7GhWuyoudCsJukNY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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