SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '6d2a6bea7ec76e482629b60163630a6e761dfcb480739e019715a4c2533eef2e' 
  AND token = 'Hf2kehANuezpg2zukRC3MWx7gboZ/i0eFPLW5fFRNHY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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