Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '21f4b7b3bce1c54c3690e10affd352e7260e9c52781a0429ac7684960c23bb83' 
  AND token = 'ObV+NLPxZg/UrDkFQBKnve4AO7i3a5G9iv8ntB8N64k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}