Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '75ba60a606e71d1ee2b5213c781e9a6ad9acb81c65b3b6408c8ae1e4f9bd6505' 
  AND token = 'xr9WZ40WC08IsRrgNoBUXs8fhDzXUJDMIH8ZXlF7Izk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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