Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '71cea4467747de589fbc7e2efc0bb5683f2dee890eba5fb1855582594dc3c5bc' 
  AND token = 'IuObVuEPvwy+6mdOYAI826MamBkBnOcJKhUML85qQRI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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