SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c2999aa9be4875170b6b4753fa47c1fb15b83140c8413e5f692a74eade5220a' 
  AND token = 'cl568rCoyN5ZzKoftQxjJQ0CWlXkNyyxrP5TpqpJicA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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