SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'fd4568b8a43144b07ef644e41b7ffd9b076ee2d15bed6bd1a10d9ab681d1b4f2' 
  AND token = 'DJ3u+bdiqYC5D8NSOjooJWX/oTuqetUDvP/8+dlxcVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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