SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '009a7c3e497cfa04db0e1863db7562928534fef05598bc17441195c52e3bc40f' 
  AND token = 'H2ZGTGLUBFUa+SCwJzICc9TpJK+7kFFbCcjr+6kxZng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}