SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '1a3fd9bf9675018a450ecc4fb8a05eaa953a7cc0709e4d2d315ad35ac368aade' 
  AND token = 'SK2+yAVqVuqFbDx+TTAGE+UIfjO3t1nTQgYZqnoeotg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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