SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'dbfc11cf36754ffff7dc0a30756e8fa0be28b4d833f0a11772da5c01dfdea2da' 
  AND token = 'XGcwFu/x6y84OudKV8LOD5/yRSM5s44rQYoDftsxvBc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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