SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '8dce034380951619d48d7dff6651d286c2c6333603e7d197ba19aa34c8dacc6b' 
  AND token = 'Zv/B+4sv/SrJM8CiPwjTK9YmVMTiI5kpZR851sGmyUg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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