SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '4ed48c19947d7c2720cfc7d1594ee2db4b50330bebfd3b095594e28d2d055df9' 
  AND token = 'WCO1E8mP1ZFy9UHU0rRPWvdjrgDom47BDwxPzkUUdHg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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