SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '3fea1d0e3716335fcba2284e976344341e94d1329ac825294bd98dcf9fb9de22' 
  AND token = 'rey+wtwHx8cCf0Ucd+S++xKDZOPIDozfN20Np3V8R6Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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