SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe64d30ef7be76ddb37ae6578dc8ffb4c849efdc0cbaa94fa701569f5338b062' 
  AND token = '3AVDEUgRHEEwIdnRsU6Y2s++EranmRevCtRyPBlghQ8=' 
  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"
    }
  }
}