SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9f46ab573f21ddc9e5b36c716a1e8062e840e61e57f646b4db984dfbd86e533' 
  AND token = 'RJSPkbOdqgi1u27Yi5pvez4CRljJFQXw9D2WyuKzB5Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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