SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'eeba875766ffe3548bac3b85dc3bee9cfc5dce9610ef1e3c789ff26d334776fe' 
  AND token = '03/J3XLSxG5Mz18tz1hEy83yzi8CiXLtC5vmuTVu7As=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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