SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9855a4cfb0fe6f321484e34387ceb54b8d19bbcdf7e7724c49bab185cdd6aafb' 
  AND token = 'B4Rjw6tCelJHkTgUSOsmUIUEkg03VzSaX/n54PsNXwY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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