SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f1efc0cff817b0706616042541dd13f966b3f8f041f345c5dcbf5a2d14dfd39' 
  AND token = 'XqRMOffzVD50hgN8p7ITeVW6d5mAB+oOyhMK3wTMsUc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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