SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b267a26223d3ccb5a15272a290523e611830575e6ccd48a72d5b79eede6ba591' 
  AND token = 'nWUli/yxGRJoZYWVUiVuRtBAT5gMZE5UNobWlSoXULk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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