SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27c4feea3eb278ced54387d8f8ce27105c60f885a275aa47b6794a12882c3ab9' 
  AND token = 'UjZb80qIvwOKA/xirvjEdKFc3A1sMDpbdwytOpBTLl4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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