Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'd0f1eef6d10e06027034904385c615b8d8d45296397e255c2c22eddf5a0ecb57' 
  AND token = 'dDBejKOWbkOGLn10GkDDq0MsBNWHzzq/TmMZTOBZmgA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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