SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'b44902a5364c5ad538dd6967901df79cc540e65d96d747ae33a60d6044cb1bf7' 
  AND token = 'YrnJ6AaAwSevL/6xFSNFehbOeTdUTn64Hcu7d4ljELw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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