SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ffbf46c97413a98291b5b9a84326c8b7d0af97694e6a960842ffa7811125092a' 
  AND token = 'JXlHeLMhRmq5fjrdaiQQV292pkCBuIlLi+rIzZeSiyg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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