SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4f31f785b26408ff4b96b1ec3e8b7ef8e24d5929bc70c7dcb6306769d33e80e' 
  AND token = 'dNlKTWyXGnodcv+AHmQ7yyUox3Pin4QRH+gDvUuVqqw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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