SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38b5e970bbaec5443102220cdc4381be0ad229dc1134bb3456ff463eda6ff848' 
  AND token = 'RvREYRf4m69ItwJvcyquNPcTyY6QYyA+ArRTBO77J7k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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