SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f3d30586ce7a59b214700dcb284bec00a7c5734c9169aabad168d836fa66139' 
  AND token = 'MI5WDHRAqlZhT6Qf/FByvyuo+qNaDJQnNuQ2BFb5kZU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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