SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '6c2ae202177303b3a8d8cfb3099b7e7ddbd3094c840218a38f588077b980bff4' 
  AND token = 'gQlfRdu7Y/SYOdnZDs+q41nXJPZEknwc8dnV3f+hO5g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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